1 Introduction and Preliminary Considerations

Transcription

J. J.
Universität Paderborn
Fakultät für Kulturwissenschaften
Institut für Medienwissenschaften
Diplomarbeit in englischer Sprache:
A critical Exploration of
Web Usability Guidelines and
Design Principles
with respect to the
special Needs of Elders
Vorgelegt am 17. Juli 2006 von
Kai Alexander Lohr∗
bei
Prof. Dr. rer. nat. Gerd Szwillus
∗ Breslauer
Straße 5, D-45739 Oer-Erkenschwick, Telefon: (0 23 68) 69 38 87;
Matrikelnummer: 6108400
Eidesstattliche Erklärung
Ich erkläre hiermit an Eides Statt, dass ich die vorliegende Arbeit selbständig und ohne Benutzung anderer als der angegebenen Hilfsmittel angefertigt habe; die aus fremden Quellen direkt oder indirekt übernommenen
Gedanken sind ausnahmslos als solche kenntlich gemacht.
Die Arbeit wurde bisher weder im Inland noch im Ausland in gleicher
oder ähnlicher Form einer anderen Prüfungsbehörde vorgelegt und auch
noch nicht veröffentlicht.
(Kai Alexander Lohr)
Ort, Datum
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Contents
1.1 Age-related Terminology . . . . . . . . . .
1.1.1 Normal Ageing . . . . . . . . . . .
1.1.2 Elders and Seniors . . . . . . . . .
1.2 On Guidelines and Principles . . . . . . .
1.3 Aspects Addressed in this Work . . . . . .
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3 Selected Ageing Effects on the Human Body and Mind
3.1 Sensory Processing . . . . . . . . . . . . . . . . . . . . . .
3.1.1 Skin Senses . . . . . . . . . . . . . . . . . . . . . .
3.1.2 Hearing . . . . . . . . . . . . . . . . . . . . . . . .
3.1.3 Vision . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Cognitive Processing . . . . . . . . . . . . . . . . . . . . .
3.2.1 Reaction Times and Rate of Information Processing
3.2.2 Attention . . . . . . . . . . . . . . . . . . . . . . .
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2 Seniors and the Web: Programmed Conflict?
2.1 The Digital Divide and how Seniors use the Internet . .
2.2 Elements of Innovation Diffusion Theory . . . . . . . .
2.2.1 Pre-Adoption Stages: Knowledge and Persuasion
2.2.2 Adopter Characteristics . . . . . . . . . . . . .
2.2.3 Adoptee Characteristics . . . . . . . . . . . . .
2.2.4 Other Theories of Technology Acceptance . . .
2.3 Possible Age Slope Explanations . . . . . . . . . . . . .
2.3.1 Adoptee Perspective . . . . . . . . . . . . . . .
2.3.2 Adopter Perspective . . . . . . . . . . . . . . .
2.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . .
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Contents
3.3
3.4
3.2.3 Memory Development and Implications for
3.2.4 Notes on Intelligence and Problem Solving
Mobility and Fine Motor Skills . . . . . . . . . .
Summary and Conclusions . . . . . . . . . . . . .
Learning
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4 Web Usability Recommendations
4.1 Facilitate Perception . . . . . . . . . . . . . . . . . . .
4.1.1 Text Formatting . . . . . . . . . . . . . . . . .
4.1.2 Colours and Graphics . . . . . . . . . . . . . . .
4.1.3 Audio- and Multi-Media Content . . . . . . . .
4.2 Facilitate Handling . . . . . . . . . . . . . . . . . . . .
4.2.1 Scrolling versus Paging . . . . . . . . . . . . . .
4.2.2 ›Seek-and-Hide‹ Menus . . . . . . . . . . . . . .
4.2.3 Click Targets . . . . . . . . . . . . . . . . . . .
4.2.4 Input Elements and Keyboard Use . . . . . . .
4.3 Reduce the Likelihood of Distraction . . . . . . . . . .
4.3.1 Advertisements . . . . . . . . . . . . . . . . . .
4.3.2 Ornamentation . . . . . . . . . . . . . . . . . .
4.3.3 Disruptive Navigation . . . . . . . . . . . . . .
4.4 Keep Users in Control . . . . . . . . . . . . . . . . . .
4.4.1 External Applications, Downloads, and Plug-Ins
4.4.2 Pop-Ups and New Browser Windows . . . . . .
4.5 Reduce Complexity . . . . . . . . . . . . . . . . . . . .
4.5.1 Text and Language . . . . . . . . . . . . . . . .
4.5.2 Site Structure . . . . . . . . . . . . . . . . . . .
4.5.3 Page Layout . . . . . . . . . . . . . . . . . . . .
4.5.4 Help and Contact . . . . . . . . . . . . . . . . .
4.6 Provide a Sound Base for Navigation Decisions . . . . .
4.6.1 Navigation Paradigms and Tools . . . . . . . .
4.6.2 Link Labelling . . . . . . . . . . . . . . . . . . .
4.7 Examples from the Web . . . . . . . . . . . . . . . . .
4.7.1 News: spiegel.de . . . . . . . . . . . . . . . . . .
4.7.2 On-line Pharmacy: docmorris.de . . . . . . . . .
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Contents
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4.7.4
Travel: bad-sassendorf.de . . . . . . . . . . . . . . .
Public Authority: kreis-recklinghausen.de . . . . . .
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5 Final Remarks
5.1 Conflicts and Inspirations . . . . . . . . . . . . . . . . . .
5.2 Ageing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Technological Innovation as a Social Process . . . . . . . .
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Appendix
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v
List of Figures
2.1
2.2
Internet usage for 2004 in selected European Union countries
by age. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of selected Internet services in Germany by age-groups
4.1 Economy section on the Web site of Spiegel Online .
4.2 Home page of the DocMorris Internet pharmacy . . .
4.3 Third-level page from the Web site of Bad Sassendorf
4.4 Home page of the German district Recklinghausen . .
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In many western countries, a generational shift is currently in progress. The
large generations born directly after the Second World War are approaching
retirement and a continuous decline in birthrates has caused the traditional
age pyramid of population to morph into a rhombus-like shape. The portion
of the populous commonly referred to as ›the elderly‹ or ›older adults‹ has
been growing in size, relative to the rest, and is likely to continue to do
so (see, e. g.: destatis 2003)1 . Various businesses begin to acknowledge this
shift by marketing products and services that also address the requirements
of the new consumer group. Originally available and of interest only to
scientists, the World Wide Web, hereafter referred to as the ›Web‹, is now
being used by millions of people around the world.
The Internet and the Web as its user interface increasingly permeate
every-day life. Media and communication technology are becoming an integral part of products and services in many fields of application. They
also act as business and distribution channels and in these capacities, their
use can result in considerable cost savings. The increasing reliance on communication technology in transactions of various kinds mandates that the
technology itself as well as the necessary skills and knowledge to use it be
available to all. Otherwise, individuals without access to these prerequisites
would be excluded from social, economic, and eventually even from political participation. Practises exist to ensure that technological appliances
are safe and easy to use for as many individuals as possible. The Internet
and the Web are no exception. The tensions between Internet and the Web
on one side and the phenomenon of ageing on the other mark the overall
area of interest for this work.
1
Statistisches Bundesamt, Wiesbaden; henceforth referred to as destatis.
1
1.1 Age-related Terminology
To establish a clear understanding of the concept of ageing, a few notes
on terminology are inevitable. This is especially true as quite different
interpretations of the term old exist. The following considerations lead up
to the definition of two terms, ›seniors‹ and ›elders‹, which shall find use
as a means to address the intended “target group”.
Expressions of age “borderlines” or ranges with arbitrarily drawn age
intervals, typically in the guise of terms like ›Generation-n+‹, frequently
appear in common discourse. The group of the 14–49 year-olds is a suitable
example. As far as media planning and advertising are concerned, it is the
most important consumer group (see: Bieri et al. 2006, p. 19). Retirement
by law currently occurs at age 65 in Germany, but only recently, the government agreed to raise the retirement age for younger generations gradually
to 67. Backes & Clemens (2003, p. 23) hold that actual retirement age, averaging around age 60 in Germany, traditionally is one of the most formal
age borderlines, but different social systems may impose others, some of
them uncannily early. The age of de-facto retirement may be such a case,
depending on the line of work. As far as the modern day labour market
in Germany is concerned, employees aged 40 years and over, depending
on their education, might well be considered old and quite unlikely to find
employment again, should they loose their jobs (see: Gourmelon 1994, p. 6).
For research purposes, categorisations based on chronological age are a
common occurrence. Spirduso (1995, p. 7) gives an insightful summarising
comment regarding categories of “oldness” : »Reviewing several research
studies will show that subjects ranging in age from 35 to 100 have been labelled ‘old’.« She goes on to say that there are no established standards for
age categories. Solely utilising chronological age as a determinant, her proposal yields four different categories: Young-old, Old, Old-old, and Oldest
old (see also Table 1.1).
Backes & Clemens (2003, p. 26) similarly see the need to subdivide what
was formerly the single phase of old age, but choose to do so based on
functional abilities: Those still able to provide or care for someone other
2
Table 1.1: Chronological age categories (abbrev. from Spirduso 1995, p. 8)
Age (years)
25–44
45–64
65–74
75–84
85–99
100+
Term
Adult
Middle-aged Adult
Young-old
Old
Old-old
Oldest-old
than themselves and to generally function normally make up the group of
the young old, those self-sufficient but unable to provide or care for another
person are the old, and finally those, who require assistance in day-to-day
living are the old-old. Note that these categories not necessarily conform
to the age ranges given in Table 1.1, although they bear similar names.
1.1.1 Normal Ageing
In order to obtain a way to fitfully restrict the “target group” in this examination, it is imperative to establish a concept of normal ageing effects in
contrast to pathologically induced effects. For this purpose, Spirduso (1995,
pp. 6–7) offers a useful set of terms: primary ageing encompasses such processes as occur naturally and are independent of environmental factors
(e. g. injuries sustained, man-made health hazards endured, or other forms
of abuse) and diseases, whereas secondary ageing includes the interactions
produced between the aforementioned external factors and primary ageing.
Smoking and obesity are good examples of environmental factors. Both are
commonly considered risk factors for stroke (disease), which in turn might
hasten the natural deterioration of certain physical and cognitive abilities.
Directly defining normal ageing as primary ageing is immensely impractical, however, as some amount of secondary ageing cannot be avoided.
Some extend of disease, injury, or abuse has to be incorporated into normal ageing. Goldstein & Ritter (1997, p. 528) employ a differentiation between impairments and disabilities to describe different manifestations of
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reduced hearing. The spirit of their interpretation can serve in this broader
context as well: by this definition of normal ageing, a normally aged individual may experience impairments, that is to say hindrances or nuisances,
but no disabilities, which are understood as conditions prohibiting complete self-reliance. This is not meant as a means to discriminate against
persons with disabilities. The rather pointed wording is necessary to enable a clear differentiation between usability enhancements benefiting older
Internet users and special requirements involving non-standard computer
interaction methods, which are beyond the scope of this document.
1.1.2 Elders and Seniors
Simply stating a floor and possibly a ceiling age to define the actual subject
group of this examination would be the wrong approach. Different systems
within a single body may, depending on the individual secondary ageing
history, age at a different rate: »An individual can be 75 years old chronologically but have a 65-year-old heart and a 85 year-old gastrointestinalsystem« (Zarit & Zarit 1987, p. 22). Similar differences show in studies that
evaluate the performance of older subjects: result plots show a broader deviation.
This definition instead approaches from the functional perspective: ›elders‹, or the adjective ›elder‹ henceforth describes persons (1) not suffering
from a disability that prevents them from interacting with a computer in
the “normal” way by using a display, a mouse or mouse-like device, and
a keyboard, and who (2) experience some age-related deficiencies as part
of normal ageing, such as those discussed in chapter 3. Thereby, chronological age is removed as a dominating facet of the definition and the only
relation to it is that impairments of any kind tend to show after a certain
chronological age.
The material reviewed in chapter 2 on Internet usage varies in fineness
of the applied age intervals and also in which age-group is the oldest. As
Backes & Clemens point out, retirement usually marks the transition to a
phase of life that is completely different from the phases preceeding it. For
example, it no longer revolves mainly around work or the upbringing of chil-
4
dren and may allow the pursuit of other interests. Owing to achievements
in health care, it is likely to go on for quite some time before life moves on
to the terminal phase with death at the end. Thus, the term ›seniors‹ or
the adjective ›senior‹ describes elder individuals who have retired.
1.2 On Guidelines and Principles
The title of this document includes the terms ›usability guidelines‹ and ›design principles‹. In a definition made by Shneiderman & Plaisant (2005,
pp. 61/66), each of these terms describes distinctly different concepts:
guidelines have evolved as best practice or advice on specific problems
encountered in a field of interface design, with their scope limited to this
particular field and often with little or no relevance outside its original
domain; design principles, on the other hand, are more general in scope
and are applicable to multiple domains, but only after context-specific interpretation. Shneiderman & Plaisant (2005, pp. 74–75) give as examples
the »8 golden rules of interface design«, but Nielsen’s (1993, pp. 115f) 10
usability heuristics also fit the above definition of principles; indeed, there
is considerable overlap between these two examples.
So sharp a distinction is not always possible. Indeed, the two terms
mentioned above occasionally even find synonymous use. The material reviewed in the course of this work was mostly labelled as guidelines, yet
in many cases the wording is sufficiently vague so as to be of little direct
use without interpretation in every individual case of application. Some
guidelines come to resemble design principles in the sense of the above definition. Consider as example Kurniawan & Zaphiris (2005, p. 131): »Screen
Layout, navigation and terminology used should be simple, clear and consistent«. The question arises precisely what simple and clear means in each
of the mentioned contexts and also with regard to elders. Consistency is a
design principle on its very own (see: Nielsen 1993, p. 132; Shneiderman &
Plaisant 2005, p. 75), applicable to several different aspects of user interfaces (e. g. action sequences, colouration, terminology). Some guidelines, or
parts thereof, cross over from or to other media or fields of interface design
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to address rather specific problems and thereby demonstrate flexibility in
the other extreme.
1.3 Aspects Addressed in this Work
Until recently, the typical Internet user was young, male, well educated,
and probably quite successful in socio-economic respects. Considered next
to the introductory comments on the changes in the age structure of many
western societies, this raises interesting questions with respect to the influence of age on the likelihood of technology use. The examination in chapter 2 investigates these age influences in the case of Internet usage and
attempts to provide possible explanations for some of them. It establishes
at least that scepticism against new technology is caused not exclusively
by increasing chronological age. It also provides helpful background information on Internet usage in different age groups.
The effects of ageing on the human body and mind, leastways those
effects relevant for computer use without special equipment, are the central
topic in chapter 3. The discussion therein presents information on the agerelated changes in physical and mental human properties. Some of the
changes, particularly those in vision, are relatively well documented and
readily observable. Others, particularly those of a higher cognitive nature,
are more obscure and less conclusive, owing to the fact that they tend to be
harder to assess. Nevertheless, knowledge about these developments forms
the basis for the consideration of special age-related Web design needs and
in some cases, it can point to possible strategies to address these needs.
Giving condensed advice on Web design and usability is the central objective of chapter 4. The recommendations made therein base on observations made in chapter 2 and chapter 3 and on an exploration of ageingrelated and general Web usability materials. Comments and extensions
supplement the findings. These elements then aggregate into six basic and
relatively specific recommendations, which allow a comparatively direct
application to Web design issues. In their wording, they attempt to reflect
both ageing- and Web-specific problem fields.
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This chapter explores what some may regard as a contradiction: Senior
individuals and their relationship to the Internet. In a first step, this chapter will assess the existence and nature of an age-related Digital Divide.
It will also explore usage preferences of senior Internet users. It will then
present elements of the Innovation Diffusion Theory (abbreviated: IDT;
Rogers 2003) as a backdrop for the discussion of possible explanations for
the age-related digital divide in the final section.
2.1 The Digital Divide and how Seniors use the Internet
According to Wikipedia, the free encyclopedia (2006b, § 1)1 , an American
technology adviser to the Clinton administration coined the term »Digital Divide« to denote ». . . the socio-economic difference between communities in their access to computers and the Internet«, which has subsequently been employed to name differences both between countries and
social groups within countries. The focus, initially on infrastructure issues
such as access to cheap and reliable connections, moved towards differences in individual abilities and usage competence (see: Wikipedia, the
free encyclopedia 2006b, § 3). The term »“gray [!] gap”« appears in a report from Fox (2001, p. 2) to describe disproportionally low Internet usage
among US citizens above a certain age, compared to other age-groups. To
assess the nature of such a usage gap, it is necessary to review more recent
material on Internet usage with regard to the United States and the European Union on a global level and with particular attention to the situation
in Germany.
1
In cited electronic documents, the structure apparent from headings or paragraphs
will be used for reference, should other means like link anchors (designated by ),
pagination, or numbered headings be unavailable.
m
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100
90
80
% of population
70
60
50
40
30
20
10
0
16 to 24
Germany
25 to 34
35 to 44
45 to 54
55 to 64
Age group
Italy
65 to 74
16 to 74
Sweden
Source: Demunter (2005a, Table 2 on p. 3)
Note: Only the points represent actual data. The lines are given for
slope illustration only.
Figure 2.1: Internet usage for 2004 in selected European Union countries
by age.
For the United States, illustrations (see: Fox 2001, p. 4; Fox 2005, p. 1)
show a “descending stair” across the age axis and a pronounced drop of
Internet usage between the 50–64 and 65-and-older age-groups. This general appearance seems to be equally present in the European theatre (see
Figure 2.1): Internet usage decreases gradually along the age axis and
a pronounced drop occurs between the 45–54 and 55–64 age-group. The
aforementioned figure shows data for only three EU nations; still it exemplifies that even among those countries that were members of the European Union before its eastward enlargement, remarkable differences in
Internet usage continue to exist. It is also not too surprising to see that
Figure 2.1 shows a much more benign development for Sweden. The survey
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data for other Nordic countries was similar in this respect, and, in terms
of average usage, Sweden, Denmark, and Finland rank best in that order
(see: Demunter 2005a, p. 3). Also note the particularly sharp drop-off for
Germany in the 55–64 age-group, which is much larger than in the aforementioned Nordic countries. When referring to the apparent decrementing
effect that age has on the likelihood of Internet usage, it is convenient
to name the continuous manifestation the ›age slope‹ and the sharp drop
occurring between two age-groups the ›age gap‹.
Across nations and generations, there are also considerable differences
in how individuals use the Internet. For the sake of scope, this section will
discuss the issue of Internet usage preferences for the United States and
Germany only. Apart from e-mail, which is the Internet service unquestionably used most frequently by senior users (see: Fox & Madden 2005, p. 1),
Fox identify some key applications that enjoy popularity of roughly similar
proportions across the age-groups: retrieving health-related, religious, or financial information, playing on-line games, utilising stock trading facilities,
and making an Internet-based phone call (see: Fox 2004, p. 10). Regarding
other on-line transactions such as buying products, making travel arrangements, or on-line banking, Fox (2004, p. 8) observes that US seniors show
a considerable reluctance to conduct them on-line, while using the Internet
for researching them prior to actually performing them off-line does not
face so large a constraint. For most other research activities, the report
lists usage figures that are below those of the younger age-group, but it
identifies one topic that is of more interest to its senior age-group of 65
years and older: genealogy and family research (see: Fox 2004, p. 10). With
regard to more recent figures from Fox & Madden (2005, p. 3), the notion
of lower usage figures for older Internet participants generally preserves—
at least for those seniors behind the age gap at 70 years and older (see:
Fox 2005, p. 2). The difference may in some cases, however, reflect more
structural changes: seniors are less likely to conduct school research online, for they themselves do not have to attend formal educational facilities
any more. A similar rationale applies to using the Internet to search for
a job, which can be expected to be less important for pensioners. Still,
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there are numerous services used by 50 % or more of the senior Internet
users and Fox & Madden’s (2005, p. 3) figures show that to the group labelled as »mature« (aged 60–69), usage rates in activities such as product
research, news reading, banking, making travel arrangements, and even
purchasing goods and services do not stray too far from the average. Interestingly, finding health-related information on the Web appears to be
especially important to quinquagenarian Internet users and figures for the
older sub-groups are “only” around the average. Concerning more recently
popularised applications such as instant messaging, downloading games,
videos, or music, or participating in on-line auctions, findings continue to
suggest that senior Internet users are markedly below the average in these
usage categories. Fox (2001, p. 10), however, relates this effect to users’
on-line experience. With higher-aged users less likely to be Internet users,
owing to the overall age slope, the number of experienced users in older
age-groups is probably lower than in younger age-groups and thus may
contribute to this manifestation.
The available data from Eurostat2 and the German destatis is unfortunately less detailed in terms of Internet activities. The examination of the
relevant material for Germany yields e-mail and the rather generalised activity of ›searching for information on products and services‹ as the most
important Internet applications. The data from Eurostat shows e-mail to
be more important for the youngest (16–24) and oldest (65–74) age-groups
(see: Figure 2.2), whereas in the more granular destatis data, e-mail and
information searching were equally important for the oldest group of 55
years and older (see: destatis 2006, pp. 31–32). Aside from these differences, the cause of which are most likely the different age categories in
the survey data, usage patterns for these two activities do not differ too
much across the age-groups and are reasonably close to the average. Searching for on-line services and information related to travel, in contrast, does
show a difference in frequency of use in Germany, as Demunter (2005b,
Table 3, p. 3) witnesses: senior users are more likely to search for travel2
Statistical Office of the European Communities, Luxembourg; henceforth referred to
as Eurostat.
10
90
% of Internet users
80
70
60
50
40
30
16 to 24
25 to 34
35 to 44
45 to 54
55 to 64
Age group
65 to 74
16 to 74
Send/receive e-mail
Seek product/service information
Use/buy travel services*
Seek information from public authorities
Use financial services
Order goods/services**
Source: aggregated from Eurostat (2006) data for 2004, except where
indicated by * (data for 2004 from Demunter 2005b, Table 3 on p. 3)
and by ** (data for 2005 from Eurostat 2006).
Note: Only the points represent actual data. The lines are given for
slope illustration only.
Figure 2.2: Use of selected Internet services in Germany by age-groups
related information and services than are other age-groups. The material
from destatis (2006, p. 31) also supports this conclusion. Another notable
use case is financial services, which here too encompasses on-line banking
and share purchasing. In most EU member states, only very few Internet
banking users belong to the youngest age-group, many members of which
probably are not yet part of the labour market and thus unlikely to necessitate it (see: Demunter 2005a, p. 5). Particularly notable is, however, that
the usage of these financial services in Germany reaches levels above the
average for the oldest age-group (see: Figure 2.2). Material from destatis
(2006, p. 35) also offers insight on health-related Internet research, albeit
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at a lower age resolution: health-related topics have been researched most
by German Internet users in the group of 25–55 years of age (at 45 %), with
the oldest group of 55 years and older ranking second at 39 %. This mirrors
very generally the findings from Fox & Madden (2005) mentioned earlier
for the situation in the US. Similarly, the aforementioned reluctance to
conduct purchases of goods and services on-line (see: Fox 2005, p. 8) reappears in the Eurostat data as a steep age slope (illustrated in Figure 2.2)
and is also visible in the data from destatis (2006, p. 36). Regarding the
activity of downloading or playing music or games, the Eurostat survey
yields an age slope that in some EU countries features a rise for the oldest
age groups (see: Demunter 2005b, p. 4). For Germany, however, the slope is
continuous (see also Figure 2.2) and thus marks this activity as primarily
appealing to younger Germans. Conclusively, the existence of an age slope
and an age gap, visible both when examining Internet usage as a whole
and many specific Internet activities, becomes apparent.
2.2 Elements of Innovation Diffusion Theory
In IDT, two primary dimensions are the ›adoptee‹ (the innovation being
discussed) and its adopter(s) (human society, groups or individuals). In
both cases, the characteristics presented here were developed from an expost perspective. In the case of the adoptee, they can be harnessed to
predict the rate of adoption (see: Rogers 2003, p. 221), in the case of the
adopter, they provide a framework of generalisations regarding an adopter’s
innovativeness (see: Rogers 2003, p. 282). Furthermore, especially the first
two stages of the Innovation-Decision process, which precede the actual
decision to adopt or reject an innovation, are of particular interest, as it is
in these stages that the characteristics mentioned above are of fundamental
importance (see: Rogers 2003, pp. 170/174–175). The following sections
first explain the pre-adoption stages, then the relevant adopter and adoptee
characteristics; a final section provides the rationale for favouring the IDT
paradigm over other possibly relevant theories in this discussion.
12
2.2.1 Pre-Adoption Stages: Knowledge and Persuasion
Within the first stage of Knowledge, with which the decision process starts,
Rogers (2003, pp. 172–173) differentiates between three types of knowledge:
»awareness-knowledge« literally denotes awareness that an innovation exists, »how-to knowledge« deals with the proper operation of the innovation,
and »principles-knowledge« deals with the “inner workings” and scientific
principles. Awareness is obviously the starting point. It motivates further
information seeking on the part of the individual, which may also occur
during the Persuasion stage (see below) (see: Rogers 2003, p. 173). Especially for complex innovations, Rogers (2003, p. 173) reasons that more
how-to knowledge needs to be acquired in order to make later adoption and
continued use more likely; similarly, principles-knowledge can be of assistance, but is not necessarily a requirement. Based on Knowledge, ». . . the
individual forms a favourable or unfavourable Attitude toward the innovation« at the Persuasion stage, where most individuals look towards their
»near peers« for confirmation, even though other sources are available. (see:
Rogers 2003, pp. 174–175). In contrast to the Knowledge stage, which involves mainly cognition based on facts, the ». . . main type of thinking at
the persuasion stage is affective (or feeling)« (Rogers 2003, p. 175).
2.2.2 Adopter Characteristics
Rogers (2003, pp. 279–282) forms categories of adopters based on the ». . .
time at which an individual adopts an innovation . . .«: Innovators, Early
Adopters, Early Majority, Late Majority, and Laggards, presented in decreasing order of »innovativeness«. He goes on to characterise the correlation of an adopter’s innovativeness with socio-economic characteristics,
personality variables, and communication behaviour. The reader is kindly
referred to the original for an in-depth description; yet some striking key
elements useful for the general discussion in this paper shall follow. Note
that individuals can, and usually do exhibit a different amount of “innovativeness”, regarding different adoptees (see: de Jager 2005).
13
Looking back on previous diffusion research, Rogers (2003, p. 288) emphasises that ». . . many diffusion studies . . . show no relationship [with
age] . . .«, whereas some conclude that higher age correlates with earlier
adoption and others in turn claim that lower age indicates probable earlier adoption; he reasons that this does not clearly support any expression
of influence with regard to age as a primary characteristic. Rather, socioeconomic factors, a high level of education, social status (e. g. occupational
prestige), and economic status, positively relate to innovativeness (see:
Rogers 2003, pp. 288–289). For personality traits, those who adopt earlier typically exhibit traits such as high intelligence and empathy, whereas
dogmatic thinking, fatalism and adversity towards change may characterise
late adopters (see: Rogers 2003, pp. 289–290). Regarding communication
behaviour, Rogers (2003, pp. 290–291) holds that high innovativeness probably correlates with a high amount of social interconnection, travel across
social system boundaries, access to mass media, and a tendency to more
actively search for new innovations, and various other factors.
2.2.3 Adoptee Characteristics
Rogers (2003, p. 220) coins five »perceived attributes« for innovations that
determine the rate of its adoption: Relative Advantage, Compatibility,
Complexity, Trialability, and Observability, each of which the following
paragraphs will introduce. The idea that sceptical individuals may view an
innovation in a different light than its supporters is implicated, as already
related in subsection 2.2.1.
The Relative Advantage of an innovation constitutes improvements or
benefits, often relative to earlier ideas. The type of improvement or benefit mainly depends on the type of innovation in question, but may be
on economic grounds (e. g. increased profits, productivity, cost-benefitrelation, improved functionality) or increase an individual’s social status
(see: Rogers 2003, pp. 229–231). According to Rogers (2003, p. 233), Relative Advantage, may well be ». . . one of the strongest predictors for the
rate of adoption of an innovation«. Considerations on infrastructure mat-
14
ters constitute the Compatibility attribute. It refers to past experiences,
for example with similar ideas or innovations, the prospective user’s perceived needs, past innovations that are in use and must support or must be
supported by the new innovation, but also to social values and beliefs (see:
Rogers 2003, p. 240). Problems in this field may arise from technical issues
(consider e. g. a new type of PDA or mobile phone: failure to make provisions for PC and specifically Microsoft Outlook synchronisation would
likely hamper acceptability), but might well involve such a simple thing
as a product name3 (see: Rogers 2003, pp. 250–251). Another important
aspect in this context is what Rogers (2003, p. 254) calls the »empty vessel
fallacy«: already present knowledge can make the diffusion of an innovation
either easier or more difficult, and ignoring persistent knowledge means to
deny the importance of compatibility.
Another key variable is Complexity. This obviously denotes a relationship between the perceived or actual complexity, ease of use, or ease of
understanding, and how well the innovation will diffuse (see: Rogers 2003,
p. 257). This characteristic appears to be of exceptional importance for innovations involving computers and related technology, for in the past it has
shown to be a particularly strong hindrance to adoption (see: Rogers 2003,
pp. 257–258). In general precedence, however, Rogers (2003, p. 258) ranks
Complexity after Relative Advantage and Compatibility in that order.
The two remaining factors both govern aspects of contact with the innovation: Trialability encompasses the possibility of »trying out« (Rogers
2003, p. 258) the innovation prior to an individuals own decision to adopt.
Observability refers to how easily the innovation can be “seen in action” or
the results of its use become visible in public or private environments and
thus reach out to individuals not directly in contact with the innovation
or its owner (see: Rogers 2003, p. 258). Both attributes areconsidered to
be positively related to quicker adoption; regarding Trialability, however,
Rogers (2003, p. 258) remarks that it is probably more important to earlier
adopters, as they lack precedents of use of the innovation in their vicinity.
3
which can have a derogatory or even taboo meaning in other languages
15
2.2.4 Other Theories of Technology Acceptance
The author is aware that IDT is not the only model available for innovation
or technology acceptance discussions. Venkatesh et al. (2003), for example, propose a unified model that encompasses elements of several theories
used in research on the acceptance of information systems, among them
IDT. Their Unified Theory of the Acceptance and Usage of Technology
(UTAUT) identifies age and gender as moderators of the influence of two
primary factors largely corresponding to the IDT adoptee characteristics
of Relative Advantage and Complexity: the impact of the UTAUT performance expectancy (advantage) construct is less important to women and to
older individuals, whereas the effort expectancy (complexity) construct is
actually of more importance women and older individuals (see: Venkatesh
et al. 2003, pp. 449–450). The UTAUT model, however, addresses technology acceptance at organisational level, whereas the framework put forth by
Rogers is especially suitable for the more general discussion featured later
in this chapter, because it allows a more detailed appraisal of the adopters.
2.3 Possible Age Slope Explanations
The following passages will attempt to categorise plausible explanations
for the age gap and slope observed in section 2.1 by moving along the
characteristics IDT as outlined in section 2.2.
2.3.1 Adoptee Perspective
For a variety of reasons, Internet use may provide a considerable relative
advantage. With increasing age, individuals are more likely to have or develop health problems or chronic illnesses—despite an overall lengthened
lifespan (see chapter 3). The Internet can (and does, see section 2.1) serve
as a source of information on health-related topics. It may help to maintain
as independent a lifestyle as possible, easing the effects of restricted mobility (see section 3.3) by enabling users to order goods and services and have
them delivered to the door, or conduct dealings with various institutions
16
(public, financial, or other) from home. The Internet can also provide information, services, and opportunities regarding hobbies and various leisure
activities, with travel being of particular interest (see section 2.1). As another example, e-mail and on-line communities provide opportunities to
maintain or develop social relationships and contacts. Numerous advantages of Internet use are identifiable, relative to continued non-use; some
of them may even be of increased benefit specifically to seniors.
With regard to complexity, computers and Internet access, despite efforts
to the contrary, still require a considerable amount of non-trivial computer
knowledge or third-party help during set-up and configuration. Knowledge
acquired during pre-retirement careers may be out of date, as the development of hardware and software proceeded at a remarkably high pace. Additionally, Web site design is traditionally diverse and there are very loose
standards or conventions at best; thus, strategies successfully applied on
one Web site may fail on another, increasing the overall complexity. Furthermore, non-informational content, be it additional animation, sound,
video, or, the purest form, advertising, is often part of the page display.
Advertisements in particular are not always4 clearly distinguishable from
the informational content and again increase overall complexity. In conclusion, a considerable learning effort may be necessary to master the use
of one or, depending on prior experience, even two media elements: the
computer and the Internet.
Computers and the Internet integrate increasingly well with other media
and communication equipment of recent date, for example mobile phones,
PDAs, fax machines, cameras, television, video, and music playing devices.
Some of these, most notably mp3 players, actually developed as an extension to existing or expanding practices or technological innovations in the
computer and Internet sphere. Interfacing with older equipment such as
analogue audio or video devices likely requires more in-depth knowledge or
assistance. Internet access solutions that utilise a television set as display
may be an exciting opportunity, because they side-step the need for computer knowledge. Indigenous knowledge or prior experience—acquired from
4
depending on the layout
17
earlier forms of information technology, or during the completed phases of
Internet diffusion—may be non-existent (no contact with computers or Internet at work or prior to retirement, as appropriate), second-hand (e. g.
from other media), not much help (contact prior to wide-spread Internet
use), or even conflicting (e. g. fear of job loss due to IT-based rationalisation). Therefore, interactions with computers can be assumed to appear
radically different from established behaviour and thus likely to be perceived as incompatible.
Even though computers and Internet access have become more portable,
they largely take place in stationary settings. Consequently, observability
and trialability are limited to such settings, many of which have an educational or occupational characteristic and are thus observable to restricted
groups. Leisure use would most likely take place in private; even public
use is usually limited to certain localities, such as Internet cafes. Still,
to the actively interested individual, access to and information and training on the new technologies are available from community colleges, public
libraries, and private organisations. More easily and above all passively
available indirect observability of computer and Internet use and also of its
consequences is available through various amounts of media coverage.
2.3.2 Adopter Perspective
Especially the statements made in the previous passages on observability, trialability, and compatibility have already hinted at a social and thus
communicative aspect. With increasing age, the number of an individual’s
social connections may be subject to some decline, because after retirement,
employment and thus participation in the associated social system largely
cease and the individual’s peer group, subject to the effects of illness and
death, is mostly in a similar situation (see, e. g.: Mollenkopf 1998, p. 129;
Backes & Clemens 2003, p. 207). Most seniors are also not part of the formal education system and thus lack contact to these social systems as well:
relatively few seniors actually engage in educational activities or even academic studies (see: Backes & Clemens 2003, p. 214), although (renewed)
participation in these systems is a possibility. Mollenkopf (1998, p. 129)
18
also notes that relatives are likely to live independently. Contact with
them would therefore be less regular. Particularly disadvantaged, regarding exposure to computers and Internet use, are seniors that were already
retired before these technologies were in widespread use in employment
contexts (see: Bischoff 2001, p. 13). In some settings, there are protective
measures in effect for older individuals still in employment, which allow
these employees to decline the introduction of new information technology
into their personal work (e. g. Stadtverwaltung Aachen 1994, § 8(5), p. 5).
There is the possibility that similar agreements exist, at least in other
German communal civil service departments, and that such agreements
may shield qualifying employees from experiencing the new technological
developments themselves.
Retirement also brings about changes in media usage. For example, Lehr
(2003, p. 322) observes that in many cases, time freed due to retirement is
spent, to a considerable extend, on increased media consume—mostly focussed on “traditional” media such as television, newspapers, radio, magazines. Gauthier & Smeeding (2000, p. 21) also conclude an increase in the
amount of ». . . time spent on passive leisure activities . . .«5 with age. Earlier works (see, e. g.: Becker et al. 1991, pp. 72f; Brünner 1997, pp. 146f)
revealed a considerable discrepancy between the pensioners’ desire to lead
an active life by, for example, extending hobbies and leisure activities like
travel, and the factual implementation of such desires, although they also
acknowledge that such patterns are expected to change somewhat with the
retirement of following generations in the near future.
Other patterns of personal behaviour that can hamper the diffusion of
computers and Internet use are likely to be present among the older subgroups of the population. Traditional role models of and stereotypes on
both gender and age may discourage the adoption of this new (young) and
technical (complex) innovation, especially in older women. The widening
of gender differences in German Internet usage, as noted by Greiner et al.
(2006, pp. 50–51), is probably a manifestation of this effect: Gender differ5
The authors’ definition of »passive leisure« is media consume and relaxing (Gauthier
& Smeeding 2000, p. 35)
19
ences are apparent in age-groups of over 25 years and henceforth tend to
be more pronounced, particularly for the age-group of 55 years and older.
As mentioned earlier in subsection 2.2.4, Venkatesh et al. (2003, pp. 449–
450) recognise corresponding influences of age and gender in their UTAUT
model. Seniors are also reported to be particularly sceptical about their own
learning abilities; this may likewise act to discourage them from engaging in
pre-adoptive training and research for fear of “proving their incompetence”
(see: Stadelhofer 2000, p. 188) and consecutively from adopting the innovation. Similar effects are known to appear in cognitive ageing research:
Schneider et al. (1994, pp. 113–114) have reported that performance of
older participants markedly improves when researchers take care to minimise the “fear of failure”. All these factors may combine to discourage
participating more actively in the use of new technologies. To overcome
them, Stadelhofer (2000, p. 189) argues in favour of separate and gradual tutorials among fellow individuals (especially for women) and notes an
often enthusiastic usage pattern as the participants grow more confident
(and competent) as well as an enrichment in interpersonal communication
with younger relatives and other individuals.
Finally, regarding interactions with levels of education, Stadelhofer (2000,
p. 187) has found that encouraging Internet training and use among older
individuals who show interest in technology, further education, or both is
much easier than reaching out to seniors without such interests. It appears
to be well established that older generations have a lower percentage of individuals with high-level formal education (see, e. g.: Isserstedt et al. 2004,
pp. 103–104). The level of formal education would also have some effect on
other variables such as socio-economic status and thus on available monetary resources.
2.4 Conclusion
Despite considerable benefits and an increased (mostly passive) consumption of mass media, which should actually promote awareness and how-to
knowledge, a majority (75 %) of senior non-users say that they do not re-
20
quire Internet access and 34 % say they have insufficient knowledge6 (see:
destatis 2006, p. 7). Both statements can support an observation by Gehrke
(2001a, p. 29) on “encouragement” campaigns and advertisements that fail
to properly address the older target groups. Combined with less contact to
the social systems that are primarily involved with computer and Internet
deployment, restricted Trialability and Observability, and the fact that the
own peer group is mostly in a similar situation, this is likely to result in
substantial knowledge deficits regarding both usage and the numerous benefits. Without the necessary knowledge, it would be difficult for every individual to reach a positive attitude. Furthermore, socially induced and also
traditional personal behaviour patterns and stereotypes put seniors and
especially senior women, who outnumber men in the higher age-groups, in
a position that may make them reluctant to actively seek engagement. A
relatively high amount of complexity, however, makes extended amounts
of training and information acquisition essential. Finally, formal education
is quite capable of generating an Internet usage slope on its own: observe
that students’ use of the Internet has reached soaring levels across the EU;
a high level of education as a positive influence can be considered to be
readily established (see, e. g.: Greiner et al. 2006, p. 51; Demunter 2005a,
pp. 3/4). This appraisal is far from complete, off course, and at a rather
macroscopic level. Nevertheless, it manages to highlight that there is more
behind age-slope and age-gap than a generalised stereotype of age-related
scepticism towards technological developments.
With regard to usability and design recommendations, the findings from
this chapter allow for four main conclusions. Senior Internet users may have
less experience overall with both computers and the Internet, which leads
to the first assumption that seniors using the Internet are more likely to be
novice users. Secondly, there is evidence to suggest that a socially or culturally induced lack of confidence in their own abilities may, in combination
with their limited experience and knowledge, cause senior individuals to
behave very cautiously. The base of the third assumption is that seniors not
6
Item named ambiguously; could refer to knowledge about the Internet in general or
to a lack of skills.
21
living in English-speaking countries are less likely to be familiar with the
English language, which is the source of many technical and jargon terms.
Therefore, computer and Internet jargon may form an additional language
barrier, not exclusively for senior users , but for them in particular. As a
final note, statistics (see, e. g.: destatis 2006, p. 8) show that senior Internet users also are less likely to be using broadband connections, despite
the fact that broadband access is becoming increasingly commonplace in
many western countries. The bandwidth available to senior Internet users
is therefore still likely to be subject to the limits of modem or ISDN connections. This carries additional weight because statistics also show that the
vast majority of senior users, due to retirement, connects to the Internet
from home and no longer has access to facilities at work.
22
3 Selected Ageing Effects on the
Human Body and Mind
It is not possible to give a full and thorough examination of how ageing
affects the human body and mind within the scope of this document. Nevertheless, some illustration regarding those physical and cognitive abilities
important for accessing the Web are necessary in order to evaluate guidelines with regard to elders. The main subdivision in this chapter is between
sensory processing and cognitive processing, which, although the distinction is not necessarily made like this in cognitive literature, here serves the
purpose of organising the discussion of ageing effects on relevant human
abilities. High levels of physical performance, although they have proven
useful in predicting some aspects of cognitive functioning and health as
well, are not of particular importance for using computer systems. Therefore, a single section shall briefly discuss mobility and fine motor skills
only.
3.1 Sensory Processing
Those sensual modalities relevant to computer use shall be discussed in
sequence of increasing importance, beginning with a more brief section on
skin senses. Audio signals in various forms and applications have not yet
become a standard feature of Web sites, but their importance is evident
through secondary and audio-visual content. The focus of the discussion
will be on vision.
3.1.1 Skin Senses
Sensual modalities involving the skin are of peripheral importance only
because they do not feature primarily on the Web itself. The idea of con-
23
veying haptic information in addition to video and audio signals to the
computer user is much more readily embraced in the computer gaming
context, where technologies such as ForceFeedback find use to enhance the
gaming experience, most often in the form of vibration or resistance. Logitech, a well-known manufacturer of computer mice, joysticks, and other
input devices, did indeed try to introduce some form of haptic feedback
mouse several years ago, but discontinued this venture, as it turned out
to be unsuccessful on the market (see: König 2006). The devices apparently used vibration to create a haptic impression or hints at clickability
of whatever was under the pointer (e. g. window borders, buttons).
Skin senses are more significant for evaluating ergonomics or the suitability for elders of computer input equipment such as keyboards and mice,
which is beyond the scope of this document. Nevertheless, it is worth noticing that their sensitivity is also subject to change with age (see: Zarit &
Zarit 1987, p. 26). Skin senses include three subtypes of mechanoreception
(related to skin deformation: touch, pressure, vibration), temperature, and
pain; most of these experience some form of age-related decline (see: Plattig 1984, pp. 421/423; Verrillo & Verrillo 1985, p. 16). Verrillo & Verrillo
(1985, pp. 16–22) offer a more detailed discussion especially with regard
to vibrosensitivity, which they find to decline steadily with age for most
vibration frequencies except 25 Hz. A combination of reasons can account
for this development, most notably decreasing numbers of receptor cells,
reduced conductivity of the central nervous system (which serves as transporting channel for the gross portion of each of the skin senses), reduced
circulation both in the periphery and the brain, skin growth and ensuing
insulation of nerve ends, and influences of skin and body core temperature
(see: Plattig 1984, pp. 423/425; Verrillo & Verrillo 1985, pp. 17/19). There
are findings indicating that multi-modal feedback with a haptic component might be beneficial to older computer users (see: Emery et al. 2002,
p. 51). This result is, however, rendered academic unless such input devices
become broadly available.
24
3.1.2 Hearing
A decline in hearing ability is part of the general stereotype of ageing,
and at times receives illustration through everyday experience: an elderly
CRT computer-display in the office of an older employee emits a highpitched sound that leaves the occupant of the room perfectly untroubled,
but severely annoys younger colleagues as soon as they enter. Age-related
changes are widely recognised as being responsible for this, as the following
discussion shall show. As already mentioned in the introduction of this
chapter, the relevance of this process is supplemented, given the fact that
computers usually incorporate sound-producing gear today, but it weighs
less heavy than the changes in vision. Still, audio content may be present on
the Web, for example as a supplemental material, as part of video content,
or as auxiliary (Web site texts read out through software).
The term presbycusis encompasses progressive age-related hearing loss.
Authors generally attribute this condition to hair cell damage in the inner
ear (see, e. g.: Bayles & Kaszniak 1987, p. 151; Goldstein & Ritter 1997,
p. 530), or consider mechanical damage in lieu of or combination with impairments on cellular level, emphasising that purely age-related changes are
not so easily identifiable (see: Verrillo & Verrillo 1985, pp. 10–11), in contrast to the case of presbyopia (see subsection 3.1.3). A gradual diminishment in the ability to hear especially high frequency sounds—as portrayed
in the introductory example—is the result most common in the aged populace (see, e. g.: Bayles & Kaszniak 1987, p. 153; Krauss Whitbourne 1996,
p. 26). This decline progressively occurs throughout adulthood and an increasing difficulty in pitch discrimination accompanies it (see, e. g.: Verrillo
& Verrillo 1985, pp. 11–12).
Some authors relate that presbycusis affects men more severely than
women, possibly due to more frequent or longer noise exposure, workrelated or other (see, e. g.: Krauss Whitbourne 1996, p. 26; Goldstein &
Ritter 1997, p. 530). This would suggest an additional environmental component with influence on the development of hearing abilities. Goldstein &
Ritter (1997, p. 531) furthermore venture that age alone may not necessarily induce progressive hearing loss, as members of pre-industrial societies
25
without contact to loud environments apparently fail to display such development.
Although presbycusis may be more or less noticeable, depending on the
individual extend of the hearing loss, its impact on every-day functioning
remains relatively benign unless it impairs speech intellegibility. Sound frequencies between 0.4 and 3 kHz typically make up human speech, which
roughly corresponds to the “sweet spot” of human hearing between 2 and
4 kHz (see: Goldstein & Ritter 1997, p. 353). As Fozard (1990, pp. 160–
161) reports, reception of these speech-relevant frequencies are also subject
to age-related decline, but more slowly than high frequencies, at least until the age of 60 years; after that, the decline progresses more quickly.
Kausler (1991, p. 102) also points out that in addition to changes of a
receptional nature, central processes probably play a role in causing age
differences in speech understanding. Aside from this processing aspect and
focussed on the overall development of hearing abilities as Verrillo & Verrillo (1985, p. 13) illustrate it, the notion of lower frequencies being less
severely affected prompts to infer that men, on account of usually having deeper voices, may be easier to understand. Although intelligibility
of normal speech in unaltered condition and a calm environment appears
to remain relatively unharmed until around age 70, both Fozard (1990,
p. 161) and Kausler (1991, pp. 100–102) conclude that it is most adversely
affected by increased speed of presentation, interruption, and background
noise. With regard to the development of language understanding performance under non-optimal conditions, the illustration by Kausler (1991,
p. 101) implicates that age-related decline may start much earlier than age
60, depending on the specific presenting condition. Schneider & PichoraFuller (2000, p. 161) point out that even clinically normal hearing abilities
do not necessarily imply similar performance of elders in real-world settings
with background noise and other impeding factors present.
3.1.3 Vision
It is no exaggeration to call vision the most important sensual modality. Computers, though striving to become increasingly multi-medial, still
26
rely mainly on seeing. Most information on the Web is presented in the
form of text, images, or a combination thereof. The visual apparatus and
the nervous system associated with it are definitely suspect to age-related
change. There is, off course, also a wide range of relevant diseases which
usually have a tremendous impact on visual abilities, are more prevalent
with increased age, and remain largely untreatable in cases that involve the
nervous system (see, e. g.: Schneider & Pichora-Fuller 2000, p. 168; Schieber
2006, pp. 133–134). They can, however, count as disabilities rather than
impairments (see: subsection 1.1.1) and are thus not part of this examination.
With increasing age, the human eye looses its ability to accommodate for
near vision, due to structural changes within the eye scientifically termed
presbyopia. The advent of presbyopia is perhaps one of the most notorious
foreshadows of “old age” and is directly associated with primary ageing
(see: Plattig 1984, p. 425). The lens is made of epithelium (as are, e. g.
fingernails), and continuously produces fresh cells throughout life; yet it is
confined physically, because it is situated in the eye, and therefore unable to
grow outwards (see, e. g.: Schaie & Willis 1991, p. 442). As a consequence,
cells accumulate and the lens becomes harder and less flexible with age.
Some authors (see, e. g.: Schaie & Willis 1991, p. 442; Goldstein & Ritter
1997, pp. 512–513) hold that the ciliary body, responsible for forming the
lens into shape for near vision, looses strength as it ages and thereby further diminishes the ability of the eye to accommodate, but Schieber (2006,
p. 131) attributes presbyopia to lens rigidity alone. As a result of presbyopia, the focal point for near vision moves further and further away. According to Goldstein & Ritter (1997, pp. 512–513), the ability of the eye to
accommodate declines steadily throughout adulthood, with the focal point
moving from 10 centimetres at 20 years of age to 22 centimetres at 40 years,
then drops off sharply until age 60, where the focal point is around 100
centimetres. Individual manifestations may vary, but it is generally agreed
that somewhere in the fourth decade, this effect becomes discomforting,
as the focal point moves out beyond the 50 centimetre border Goldstein
& Ritter (1997, p. 513) name as utmost comfortable reading distance and
27
requires readers to hold out newspapers or books “at arm’s length” in order to focus on the text. By the age of 60, the eye has completely lost the
ability to accommodate (see, e. g.: Schneider & Pichora-Fuller 2000, p. 169;
Schieber 2006, p. 131).
The amount of light that reaches the retina of the aged eye decreases
by roughly two thirds (see, e. g.: Schneider & Pichora-Fuller 2000, p. 170;
Schieber 2006, p. 130). Light rays reaching the eye must pass the pupil,
which with age decreases in aperture. The scientific term for this phenomenon is senile miosis and may actually describe ». . . a dynamic process acting to optimize [!] retinal contrast and overall visual performance«
(Schieber 2006, p. 131). Furthermore, normally translucent components of
the eye, namely the cornea, the lens, and the vitreous, become slightly
opaque with age, and the lens also develops a yellow tint; these changes
further decrease the amount of light admitted. Especially the increased optical density of the lens increases intra-ocular scatter, which makes the aged
eye more sensitive to glare (Schaie & Willis 1991, pp. 443–444) and also
increases the blur of the retinal image beyond correction (see: Schneider &
Pichora-Fuller 2000, p. 171). Another contributor to reduced retinal illumination is ptosis: increased elasticity often causes the eye lids to droop into
the light path (see: Schieber 2006, pp. 132–133). A decline in retinal photo
receptors is another commonly reported cause for the decreased sensitivity
to light. According to Schieber (2006, p. 132), the number of rods, the receptor cell type responsible for monochrome vision, reduces dramatically
with age.
A most interesting ramification, with regard to the overall topic of this
essay, is an age-related decrease in contrast sensitivity, the ability to discern alternating black and white patterns. Fozard (1990, pp. 155–156) establishes that both decreased amounts of light reaching the retina as well
as changes in the retina itself and the nervous system beyond are responsible for declines in this field. Schneider & Pichora-Fuller (2000, p. 172)
and Kausler (1991, pp. 91–92) come to the same conclusion and the latter
adds information on the rating of different levels of brightness: ». . . a much
larger increase in light intensity was needed for elderly subjects than for
28
young subjects to produce the same increase in perceived brightness.« A
contrast perceivable for young adults may be invisible to elders.
For the cones as the cell type responsible for colour vision, the extend of
the age-related decline still subject to some debate. Schieber (2006, p. 132)
concludes that, given the ascertained decline of rods with age, a decline
of the number of cones also seems likely, but in the past has proven to be
difficult to measure. Apart from this development at cellular level, the light
absorption of the aged lens causes difficulties in colour vision, as it specifically reduces the amount of short wavelength light that reach the retina.
Difficulties in colour discrimination are the likely result of this. Although
Verrillo & Verrillo (1985, p. 8) relate a steady decline from age 20 and onwards with noticeable changes around age 70, Fozard (1990, pp. 152–153),
summarises more conservative conclusions with little change in colour vision except for test subjects in their 80s and criticises that the observed
effects could well be limited to the testing situation. Kausler (1991, p. 95)
remarks that accuracy in colour discrimination has dropped by up to 25 %
at age 70 and 50 % at age 90, adding that this may be of relevance primarily, when fine shades have to be distinguished. Schneider & Pichora-Fuller
(2000, p. 170) as well as Schieber (2006, p. 145) characterise the aged
colour vision as gradually approaching that of (anomalous) tritanopia. An
interesting observation in this respect is that changes in colour perception
may be responsible for a preference of bright colours and highly contrastive
combinations among the elder population (see: Brünner 1997, p. 45).
Age-related changes in contrast sensitivity, colour vision, and retinal
luminance all contribute to a loss in overall acuity. Even with corrective
glasses, these factors still ». . . lead to a more blurred, lower contrast and
less bright retinal image« (Schneider & Pichora-Fuller 2000, p. 173). The
development of corrected visual acuity itself has been depicted in overly
pessimistic terms in past research; more recent studies have yielded a better
(and also more accurate) prognosis: ». . . relatively unimpaired levels of
visual acuity can be maintained “for most persons” . . . until 88 years of
age« (Schieber 2006, p. 138).
29
The aforementioned changes on a more receptional level would be expected to influence also higher-order visual functioning. Indeed, age-related
reductions in the field of view are commonly reported (see, e. g.: Fozard
1990, p. 153; Kausler 1991, p. 92). Within the field of view, targets can
be recognised even if they do not appear at the immediate point of focus.
Schneider & Pichora-Fuller (2000, p. 174) assume a reduction of more than
20 % by age 70 and relate that, full corrected acuity notwithstanding, ». . .
an older adult’s useful visual field can be only one third that of a younger
adult . . .«, depending on the visual scene in question; the authors name
presence of distractors, target/distractor similarity, and dual-task settings
as likely influences. This establishes a link to research on attention (see
subsection 3.2.2). Regarding the onset of the decline in the field of view,
Schaie & Willis (1991, p. 444) concludes that it remains steady until age 55,
then diminishes—with pronounced differences usually present by age 75.
Schaie & Willis (1991, p. 444) as well as Kausler (1991, p. 92) stress that a
strongly diminished field of view can have a profound impact on everyday
life; the latter also remarks that it may be one of the factors responsible
for the increased amount of accidents in traffic elders experience. A decline is also observed in temporal resolution, which is in essence the lowest
frequency of a flickering stimulus at which it is perceived as continuous;
elders require a lower frequency to detect flickering (see, e. g.: Schneider
& Pichora-Fuller 2000, p. 174). According to Schneider & Pichora-Fuller
(2000, p. 175), elders have a higher threshold in detecting uniform movement against a background and are less adept at tracking fast-moving
targets.
3.2 Cognitive Processing
Numerous ways exist to conceptualise cognitive functioning and to explain
the ageing effects. Borderlines between the constructs as well as the influences they exert on the assessment of one another are not always clearly
determinable. The discussion of cognitive ageing will begin with the commonly reported reduction of timed performance, observe changes in the
30
two very influential concepts of attention and memory, and end with notes
on intelligence and problem solving behaviour. As shall be evident, there
is no consent as to what is the uniform cause of age differences in cognitive
performance, or whether or not there is a single cause or more than one.
3.2.1 Reaction Times and Rate of Information Processing
Reaction times have been monitored in ageing research to asses a wide
variety of cognitive functions and consistently produced higher latency in
elder participants as result (see, e. g.: Schaie & Willis 1991, p. 453; Hartley
2006, p. 184). Related observations include more physical manifestations
as well, such as different and slower movement patterns (see, e. g.: Spirduso
1995, p. 185); as task complexity increases, the age differences in response
time generally become more pronounced (see, e. g.: Matthews et al. 2000,
p. 292).
The cause of slowed reaction was held to be the construct of central
information processing, which was investigated both as a symptom of and
a possible universal explanation for age-related declines in cognitive functioning (see, e. g.: Hartley 2006, p. 183). There have been observations
challenging the appropriateness of this very convenient perspective of relating all age deficiencies solely to reduced processing speed: experiment
tasks have exhibited systematically different slowing patterns, which have
led researchers to conclude that several underlying processes of cognitive
functioning are subject to different amounts of age-related slowing (see,
e. g.: Matthews et al. 2000, p. 293), although which processes these are and
to what extend they are affected, is still subject to research. Furthermore,
the pureness of response time as a measure has been called into question,
because laboratory tests, while still simplified, compared to the real world,
have to be sufficiently complex to produce age differences and are thus
likely to involve several age-sensitive factors at once, thereby combining
their effects (see: Hartley 2006, p. 200).
The slowing phenomenon has been attributed to age-related change of
the central nervous system: actual neural decline, reduced nerve conductivity, reduced blood perfusion, and reduced levels neurotransmitters. Cerella
31
(1990, pp. 202–203) illustrated that a neural network could be employed
to model the information processing ability of the central nervous system
and how the increased response latency could be explained as broken connections between neurons, which require detours around broken links and
thus slow the response. Even though an actual decline of the neurons themselves is in doubt and the contribution of nerve conductivity reductions
to reduced response times have been considered marginal (see: Matthews
et al. 2000, p. 293), the level of neurotransmitters, such as dopamine, have
been reported as declining with age (see, e. g.: Schaie & Willis 1991, p. 452;
Spirduso 1995, p. 268). A pathologically sharp decline of dopamine is one of
the causes of Parkinson’s disease and makes Parkinson’s patients exhibit
exaggerated slowness and difficulties in motor movements, among other
symptoms (see, e. g.: Spirduso 1995, p. 268; NINDS 2006, What_is).
Thus, a mild, natural decline of dopamine would suggest non-pathological
manifestations of similar symptoms with age.
There have also been studies indicating that physical fitness, like in other
fields of research on ageing, has beneficial influence on response speed, to
the extend that physically active elders out-perform inactive younger participants in timed tasks (see, e. g.: Spirduso 1995, pp. 272–273; Hartley
2006, p. 186). Since physical exercise increases blood perfusion, it could
thereby exert a positive influence on the brain and its functioning. Similarly, practice sessions have been reported to improve the performance
of elders, but they cannot eliminate age differences completely (see, e. g.:
Hartley 2006, p. 186). On a behavioural level, a different trade-off between
speed and accuracy in elder participants, brought about by social “pressure” to show competence and thus to make as few errors as possible, or by
a reduced ability to optimally adjust the personal speed/accuracy tradeoff based on error feedback, was also discussed as possible cause (see e. g.:
Matthews et al. 2000, p. 294).
According to Hartley (2006, pp. 200–201), reduced response times among
elders, although indubitably present, are no longer considered as a universal
cause of age-related cognitive decline. Rather, research now investigates
the interrelations between cognitive constructs, possibly present common
m
32
decline causes, and ageing, and considers processing speed ». . . as one of
several possible markers for the physiological intactness of the organism or
. . . as one of many cognitive processes« (Hartley 2006, p. 201).
3.2.2 Attention
In a functional perspective, attention is frequently discussed in terms of
selective, divided, and sustained attention (see, e. g.: Kausler 1991, p. 134;
Matthews et al. 2000, p. 294). Tasks as well as theories may, however, not
honour such distinctions (see: McDowd & Shaw 2000, pp. 221–222).
Age-related deficits in selective attention, the ability to ignore irrelevant
information, or rather to discriminate relevant from irrelevant information
(see, e. g.: Bayles & Kaszniak 1987, p. 255), have been a consistent result of
cognitive ageing research, even though certain modifiers do apply. In visual
search tasks, which require the location of a target stimulus such as a letter
within an array of distractor items (numbers, other letters, symbols), it
generally takes elders longer than younger participants to detect targets;
the performance of elder participants reduces particularly sharp for targets
very similar to non-targets (see: Matthews et al. 2000, p. 295; McDowd &
Shaw 2000, p. 228). On the other hand, singularly different targets (targets
that are discriminable by a single characteristic) may even allow elders to
perform at equivalent or only slightly lower levels than younger individuals
(see, e. g.: Plude 1990, p. 481; McDowd & Shaw 2000, p. 228). There is
also a line of research suggesting that elders perform better in visual search
tasks when a cue to the spatial location of the target is given (see, e. g.:
D’Aloisio & Klein 1990, p. 461). In attention assessment tasks that used
text reading comprehension, elders performed worse, relative to younger
participants, when the distracting material was semantically related to the
target material, particularly when ambiguity resulted from the interference;
measures to make target and non-target text more discriminable, however,
induced better performance in elder participants in this discipline as well
(see: McDowd & Shaw 2000, pp. 255–256).
Diminished performance for elders in the field of coordinating multiple
tasks (divided attention) are likewise well documented, although McDowd
33
& Shaw (2000, p. 236) note that a discussion revolves around how age
differences could be just as well explicable through differences in the demands of the individual tasks employed in the coordination tests, rather
than age differences in the ability to divide attention. In conclusion, they
list difficulty (e. g. processing or memory demands), novelty, and similarity
in stimulus or response as possible task-specific influences and also express
that ». . . aerobic fitness . . . and extended training . . . may be important
and manipulable factors . . . in attentional performance« (see: McDowd &
Shaw 2000, pp. 241–242). Task complexity as the main determiner of age
deficits in divided attention tasks is identified by Matthews et al. (2000,
p. 296), but these authors also acknowledge that it may be not the multipletask aspect per se that is age sensitive, but other processes, depending on
the specific task in question. McDowd & Shaw (2000, pp. 250–251) further
comment on switching attention from one task to another and conclude
that for simple tasks, equivalence exists or can be established after training, but as the tasks’ memory demands increase, age-related deficiencies
in the ability to switch attention become apparent; physical fitness may
again positively influence abilities here.
With regard to sustained attention, the continuous observation of stimuli
over extended periods, the picture is more diverse. McDowd & Shaw (2000,
pp. 252/254) conclude that studies suggests an ». . . age equivalence in
vigilance task performance . . .«, but acknowledge that more demanding
tasks do result in age differences. Matthews et al. (2000, p. 298) on the other
hand quote a number of studies that produced age differences mostly in the
amount of stimuli detected (or false positives produced), but not necessarily
in the rate of the characteristic performance decline, which takes place over
the time of task duration. This interpretation is in line with earlier works
on this topic (see, e. g.: McDowd & Birren 1990, p. 225; Kausler 1991,
pp. 186–187). All reviewed authors, however, sustain the notion that the
complexity of the vigilance task is related to the magnitude of the age
deficits and more complex tasks yield larger age-related deficits. Again, a
high level of physical fitness is a possible factor in better vigilance task
performance (see: Matthews et al. 2000, p. 298).
34
3.2.3 Memory Development and Implications for Learning
In cognitive research, several types or views of memory have been distinguished. The distinction between stores is based on how long a memory is
retained: sensory, short-term and long-term memory. Over time, the conceptualisation of memory has been refined to a functional perspective to
further account for experimental observations (see: Matthews et al. 2000,
p. 61). It appears that within long-term memory, a distinction between
declarative memory (sometimes referred to as explicit) and non-declarative
memory (occasionally named implicit or procedural) can be considered to
be well established on behavioural as well as neurological grounds (see:
Hoyer & Verhaegen 2006, p. 210). In this view, declarative memory is
concious (the individual is aware that memories exist and can usually
describe them verbally), whereas non-declarative memories are subconcious; examples are skills or classical conditioning (see, e. g.: Matthews
et al. 2000, p. 62; Hoyer & Verhaegen 2006, p. 210). Age-related deficits
in non-declarative memory functions have been reported as being mild,
non-significant, or non-existent (see, e. g.: Zacks et al. 2000, pp. 306/311;
Hoyer & Verhaegen 2006, p. 214), although these statements most likely
refer to retention and continued use of already learned items (see below).
This discussion will nevertheless leave non-declarative memory aside and
instead focus on those memory types with pronounced age-related decline.
An important distinction within the construct of declarative memory
is between episodic memory, which covers events, and semantic memory,
which holds factual knowledge (see: Hoyer & Verhaegen 2006, p. 213). Ageing research, according to Hoyer & Verhaegen (2006, p. 213), has resulted in
a stable consensus regarding deficits of older individuals in episodic memory
tasks. These tasks require the recollection of specific contextual information about the time, place, or situation in which the individual formed the
memory in question, as opposed to the construct of familiarity, which only
». . . involves a feeling of “recognition” . . .« (see: Hoyer & Verhaegen 2006,
p. 212). Semantic memory, although generally associated with the same
brain region, exhibits a different pattern of decline; recollection and familiarity probably draw on different cranial resources. Because it reflects a
35
person’s knowledge accumulated over time, semantic memory performance
actually increases initially. Hoyer & Verhaegen (2006, pp. 214–215) report
the age of 60 as the point whereafter age-differences become pronounced
for both episodic and semantic memory. Still, elders perform better in tasks
that do not require the recall of contextual information, such as where the
memory or knowledge originated. Zacks et al. (2000, p. 325) say that difficulties for elders have been shown to involve ». . . color [!], case, or font, . . .
[or the] temporal sequence [of target items] . . .« and also more fundamental
details such as the media type of item presentation, for example whether
photographs, videos, or speech was used, or the sex of the speaker.
The construct of working memory accounts for ». . . tasks that require
the individual to simultaneously store and actively transform information«
in what was previously referred to as short-term memory (see: Hoyer &
Verhaegen 2006, p. 217). It is in line with traditional store models and
evolved to account for these »processing issues« that they failed to address
(see: Matthews et al. 2000, p. 63). Age differences have been consistently
reported for simple memory-span tasks as well as more complex tasks involving multiple task processing, as Hoyer & Verhaegen (2006, p. 217)
report. Deficits in working memory have profound impact on cognitive
ability, because many forms of cognitive processing involve working memory somehow; among others, relations with fluid intelligence factors (see
subsection 3.2.4 and language have been established (see: Zacks et al. 2000,
p. 217; Hoyer & Verhaegen 2006, p. 302).
Apart from more general explanations such as decline of low-level sensory
functions and generalised slowing, memory decline has also been attributed
to deficits in cognitive control functions, which handle interference, multiple task coordination and attention switching, among others (see: Zacks
et al. 2000, pp.218–221; Hoyer & Verhaegen 2006, pp. 302–305). This apparently links the topic of memory closely to research on attention. Either
way, it has been shown that memory deficits are amendable to training:
application of suitable mnemo techniques can at least make age differences
smaller, although the efficacy of such measures reduces with further ageing
36
and likely depends on continued training and application in everyday life
(see, e. g.: Philipp & Kliegl 2000, pp. 99–100).
Changes in the functioning or effectiveness of memory has consequences
for learning. Zacks et al. (2000, pp. 314–315) point out how proper structuring of the learning material (in this case, the example is a word list) and reference to already present knowledge positively affect memory performance
in both younger individuals and elders. The acquisition of more complex
skills or abilities, even if they largely feature under the heading of implicit
(non-declarative) learning, do show age differences to the disadvantage of
elders, which Hoyer & Touron (2003, pp. 34/36) attribute largely to deficits
in lower-level perception and generalised slowing of information processing.
Expert knowledge, if relevant to the task or material to be learned, does
result in considerable performance benefit for both elders and younger test
groups, but task- or skill-specific experience does not necessarily lead to
a performance advantage for older experts; at least, it appears to be able
to compensate for some age-related reductions of general cognitive ability (see, e. g.: Lehr 2003, pp. 101–102; Hoyer & Touron 2003, pp. 36–37).
Among other influences, Lehr (2003, p. 94) also points out presentation
speed and complexity (lower for well-structured content) as well as motivational and environmental factors, the like of which (Stadelhofer 2000)
have already been discussed in the context of subsection 2.3.2.
3.2.4 Notes on Intelligence and Problem Solving
Intelligence itself is not an independent cognitive construct, but rather a
conglomerate thereof. With Bayles & Kaszniak (1987, p. 232), ». . . it is
difficult to find a human cognitive process that has not been included, at
one time or another, within the definition of intelligence.« Thus, intelligence
studies may serve to indicate an individual’s proficiency in problem solving
and cognitive ability, but this has to be done with caution, for in past
decades, the observed age differences in cross-sectional intelligence surveys
were one of the pillars of the deficit view of ageing, which concluded a
steady decline of intelligence with age (see, e. g.: Brünner 1997, pp. 24–25;
Lehr 2003, p. 76): cohort effects from factors like nutrition or education
37
level were too easily attributed to the ageing process and promoted an
exaggeratedly negative view of the cognitive ability of elders.
In intelligence studies, the differentiation between crystallised and fluid
intelligence is of renown and each is assessed by different subsets of intelligence test batteries (see, e. g.: Lehr 2003, p. 78). The former are more
dependent on education and experience and thus tend to show no decline
or even an increase in scores, whereas the latter tend to exhibit a moderate
decline with age (see, e. g.: Kausler 1991, pp. 723–724). Fluid intelligence
represents indigenous abilities and includes measures like inductive reasoning and spatial ability; crystalised intelligence includes acquired knowledge,
verbal, and numerical ability (see, e. g.: Bayles & Kaszniak 1987, p. 234;
Lehr 2003, p. 78). The different results when comparing cross-sectional and
longitudinal data is striking even when the methodological problems of longitudinal studies like drop-outs or positive selection are taken into account.
Schaie concludes from his long-running study series that the intelligence
decline in adulthood is much more benign than previously thought and also
greatly varies inter-individually: there are strong correlations with socioeconomic status and longitudinal studies tend to show no decline or only
moderate decline, especially among individuals for whom the continued application of academic skills is a necessity (see: Schaie 2005, p. 421). They
furthermore conclude that most individuals may experience a decline in
ability past age 60, but ». . . it is not until the 80s are reached that the average older adult will fall below the middle range of performance for young
adults« (see: Schaie 2005, p. 419).
Evaluations of everyday problem solving abilities face difficulties regarding comparison and generalisability of findings because of differences in
task and scoring approaches and a confinement of eligible age groups (see:
Marsiske & Margrett 2006, pp. 319–320). In this field, Marsiske & Margrett
(2006, p. 320) remark, studies have been largely of cross-sectional design
and thus are subject to the caveat of cohort confounding (see above). Study
results of problem-solving and decision-making, it appears, have a relationship to intelligence measures and the development of their results over time
38
is quite similar to those of intelligence studies, at least cross-sectionally
(see: Marsiske & Margrett 2006, p. 328).
Based on a three-stage model of problem-solving, where an internal representation of the problem is formed, a strategy for solution is developed
and finally applied to solve the problem, Kausler (1991, pp. 656–657) concludes that age differences may stem from a tendency to pay undue attention to irrelevant details in the first stage, from difficulties in generating an
effective solution strategy (heuristic) and increased likelihood of continuing
the use of an ineffectual heuristic rather than abandon it in favour for a new
one in the second stage, and increased caution and scepticism against the
quality of the solution at the third stage. Age differences further increase
as tasks induce increased memory loads (see: Kausler 1991, p. 657 and also
the passage on working memory in subsection 3.2.3). In Decision-making,
there is a tendency in elders to narrow the focus and consider less options.
Studies have shown elders to base decisions on less information (i. e. they
ask fewer questions, take fewer aspects into consideration than do younger
participants), but these tendencies may be a result of reduced information
processing capacities or even a strategy employed to actively counter these
deficiencies and to avoid an “information overload” or too high memory demands (see: Marsiske & Margrett 2006, pp. 324/326). Deficits in holding on
to previous but non-optimal heuristics have also been observed in younger
individuals for tasks that are of little practical interest to them; thus, the
age differences in problem-solving and decision-making, at least to some extend, may be task specific (see: Marsiske & Margrett 2006, p. 326). As has
been mentioned, older participants also appear to have less confidence in
their problem solutions. There are similar observations in decisions-making
research (see: Marsiske & Margrett 2006, p. 326), and this may be seen in
analogy to motivational aspects of engaging in new learning efforts (see
subsection 2.3.2).
39
3.3 Mobility and Fine Motor Skills
Mobility in the aged is most basically characterised by reduced speed of operation. Maintaining balance is of key importance and is achieved through
a complex interplay of sensory and neuromuscular systems, normally requiring little or no concious effort; each of these systems, however, changes
with age and balance becomes gradually more difficult to attain or reattain
after balance loss, either naturally during the movement process or through
environmental upsets (see: Spirduso 1995, p. 178). Pathological influences
and consecutively falling incidents remain the most important source of
mobility limitations. Healthy elder individuals usually are able to move
normally, but when loss of balance and falling, made more likely through
disease (see: Spirduso 1995, p. 175), become a very real risk of day-to-day
locomotion, individuals may chose to restrict their activity. Falling incidents, which usually carry severe health consequences, can start a “vicious
circle” that continuously worsens the mobility situation by increasing both
fear and likelihood of falling (see: Spirduso 1995, pp. 168/177–178). The
often observed decrement in walking speed probably reflects the necessity
for more economic energy usage and the increased difficulty of maintaining
balance; it evolves as a measure to compensate for age-related declines in
the systems involved in locomotion (see: Spirduso 1995, p. 171).
Intricate movements requiring fine motor control are usually formed and
executed in the same way across age groups, but a slowing with age and also
subtle differences in movement patterns are reported (see: Spirduso 1995,
p. 219), as are reductions in the ability to make finely tuned and precise
manual movements. For aiming tasks, Spirduso (1995, p. 220) concludes
that antagonist muscles may ». . . not be activated as quickly as is necessary
to stop the movement on the target«; she also attributes the ». . . jerky,
uncoordinated movement sometimes seen in older adults« to this reduced
ability to finely control muscular force application. Reduced inhibitory control, already mentioned earlier in the context of processing speed and in
the guise of slow decline in neurotransmitter levels (see subsection 3.2.1),
may also be responsible less accurate movement control. As with response
40
to external stimuli, Spirduso (1995, pp. 241/242) holds that elders usually
favour accuracy over speed in intricate movements.
3.4 Summary and Conclusions
The discussion in the previous sections of this chapter helped to identify
certain problem fields. In some cases the reviewed material also points
directly to possible approaches for strategies to externally compensate for
ageing effects. The upcoming discussion of Web usability recommendations
will refer to these results.
In the fields of sensory processing and fine motor skills, the findings are
relatively close to the actual functioning and therefore allow a fairly direct
application. For the domain of hearing, problems ensue mainly from the
reduced ability to understand speech, from increased susceptibility to aural
distractions like background noise or bad signal quality, and from too fast
presentation speed. These must be taken into account in the production
of spoken text or audio-visual content. Compensating strategies could be
using a deep (male) voices for recorded speech, a slow and sequential rather
than parallel presentation of stimuli (e. g. music, speech, sound effects), and
a high signal quality. Of particular interest and saliency are the changes in
vision. Reduced overall acuity is well documented as a ramification of ageing. Along with impaired colour vision, increased susceptibility to glare,
and reduced contrast sensitivity, the visual deficits call for a special effort to make optical presentations highly visible. Intensity differences for
both colour and contrast combinations have to be sufficiently pronounced
in order to be easily detectable. Compensation strategies mainly involve
avoiding certain colour combinations and very small content. Elders should
also be spared from having to detect low contrasts and fine hues. Finally,
reductions in the ability to finely control intricate movements can be seen
as a result of declines in fine motor control and skin sensitivity. These developments may impede the very precise handling of pointing and input
devices.
41
The material reviewed on attention has identified task complexity as
an important determinant of performance´, especially for elders. Closely
related are findings on the coordination and simultaneous execution of multiple tasks, where the performance of elders declines particularly sharply.
Furthermore, distractions in visual search tasks have a stronger impact on
elders. In the case of visual searching, singular identification characteristics
for targets and location cuing could form a basis for a viable strategy to
compensate age-induced deficiencies.
The age-related decline in memory capacity is a factor possibly affecting
several cognitive domains, but the direct consequence is that less information can be held directly available. Another problem field in the context of
memory is recollection, the ability to recall contextual information, which
has been shown to decline. Closely related to memory, complex learning
material is another source of difficulty for elders. Favouring recognition over
recollection may in some cases be a possibility to overcome memory problems. For learning materials, a good structure and references to existing
knowledge have been identified as facilitating factors.
The finding that elders pay undue attention to irrelevant detail in problem solving draws up a parallel to the results from the domain of attention.
Other observations in this field are a lack of confidence in self-generated
problem solutions and decisions, which parallels findings from chapter 2 on
a lack of confidence many senior individuals have in their abilities. Furthermore, elders may exhibit a reduced likelihood of abandoning a previously
successful solution strategy that fails or is no longer optimal and a tendency
to consider less options.
The numerous problem fields identified in this chapter can easily paint a
rather bleak picture of the abilities of elder individuals. It is a noteworthy
conclusion of ageing research, though, that increasing age also brings with
it increasing diversity. There may be individuals to whom several of these
age-related reductions apply, but very few will exhibit all of them. Furthermore, the performance declines associated with normal ageing usually are
without serious consequences for everyday life in many fields, especially
in the cognitive domain. Many individuals can be expected to retain key
42
abilities into their seventies or eighties and possibly further. Generalisations aimed at the whole of the elder populace are quite difficult to make,
especially with regard to the cognitive processing performance.
43
The following sections will present guidelines and findings on Web design
and usability that address special requirements elder users may have and
also includes relevant material that is not directly age-specific. Several different approaches were considered to organise these usability recommendations. For example, Beier & Vaughan (2003) propose a framework for use
with cross-product software design guidelines, which focuses strongly on the
properties of the “product”. Instead, six sections aggregate the most important recommendations, comments, and extensions and the section titles
come quite close to the initially presented definition of design princples. In
some cases like section 4.5, the titles strongly resemble the examples cited
in section 1.2. Nevertheless, most of them allude to the specific conditions
of the Web and mirror the requirements of elder users in an attempt to
bridge between these two aspects. A final section presents four short exemplary cases made on Web sites of recent date and reasonable interest to
the group of elder users.
4.1 Facilitate Perception
As mentioned earlier, the Web is still mainly a visual medium. Most of
the reviewed sources mirror this state of affairs and place a focus on visual
aspects. The following passages first deal with the readable presentation
of text on computer displays, then cover the issues regarding illustrative
graphics and colour. Finally, they comment on audio- and multi-media
contents, albeit briefly.
44
4.1.1 Text Formatting
To address the problem field of acuity, numerous sources recommend the
use of large, easy-to-read type for texts published on the Web and intended
to be read by elders. Contrary to expectations, Chadwick-Dias et al. (2003,
p. 33) found that text size did not significantly affect the performance of
elder users in their usability study—an outcome they attribute to the increased amount of space the larger text requires and the ensuing necessity
to scroll. Nevertheless, elder-specific guideline sets typically recommend
using a sans-serif type, sized to match 12–14 point on paper. Bernard et al.
(2001) report that in their comparison of reading speed and user preference
for sans-serif versus serif type of 12 and 14 point size, the sans-serif was
the preferred typeface in all sizes and read faster at 12 points, whereas the
serif type was read faster in 14 point size but never preferred. In contrast
to these findings, Lynch & Horton (2004b, § 4), generally advise the use
of serif typefaces adapted for screen use (in this case Times New Roman
or Georgia) for body text on Web pages, especially such pages as are expected to be printed rather than read on the screen. With recent Web
technology, it should be no trouble to specify an alternative typeface in
a version optimised for printing. Some publications (see, e. g.: Holt 2000,
p. 3; Bollwage 2005, p. 62) specifically denounce the use of italicised type
on screens, because the usually low display resolution (in most cases 72–96
dpi) produces a stair effect on the slanted lines and makes the text hard
to read. For emphasise, boldface is recommended instead.
On paragraph level, the elder-specific guidelines generally call for ragged
left justification to be used instead of full or centre justification, advise that
line length be kept short (to 35–50 characters), and that line spacing be
increased. These recommendations do not directly address any of the previously identified problem fields, but by minimizing the necessary eye movements and lessening the danger of loosing the line, they facilitate reading
(see, e. g.: Bollwage 2005, p. 52). The Web imposes limits, however, on the
control of typographic appearance. Line breaking is particularly troublesome to control, as fluctuations caused by screen resolution, the operating
system and browser software, and the preferences set therein make the out-
45
come very difficult to predict. Griffiths (2004, § 1.4) demonstrates how the
use of relative measures in size definitions can remedy many design issues
while at the same time improving usability by supporting browser-side text
resizing.
Recommendations on text background address problems in contrast vision and glare. To maximise the contrast, the obvious choice is black text
on a white background without patterns of any kind. Using pure white
as background, however, can cause problems on its own. This touches the
problem field of glare: Bollwage (2005, p. 62) points out that because a
computer screen basically resembles a lamp, small text, text in a typeface with thin strokes, or text in a typeface with pronounced differences in
stroke strength is particularly tiresome to read on a screen; he advises less
bright shades (e. g. beige) for use as text background and a sans-serif typeface with sufficiently strong strokes. Similarly, Ellis & Kurniawan (2000,
p. 270) reports a light yellow background for text presentation as the final
result in his participatory design study. Using actual colours as text backgrounds, even if they are off-white as suggested above, touches the problem
field of colour vision. Shades of green, blue, or violet should therefore not
be the colours used to tint the background of text on the Web if one of
these colours appears in the foreground. For illustration, consider Holt’s
(2000, p. 3) example of blue-coloured links embedded in green text or picture such links in front of a greenish background; such a combination could
seriously impede usability.
4.1.2 Colours and Graphics
Elder-specific guideline sets ask designers to generally avoid the critical
colour combinations in the blue-green (see, e. g.: Kurniawan & Zaphiris
2005, p. 131) or blue-green-yellow (see, e. g.: NIA & NLM 2002, p. 6) ranges,
thereby addressing the problem field of colour vision. Becker (2004a, p. 20)
says that in general, combinations of colours that are spectrally similar
cause difficulty in distinguishing between them and combinations of highly
saturated colours in close proximity are very tiring to the eye because
they require it to refocus continuously. Lynch & Horton (2004a) state that
46
because ». . . most Web users have computers and monitors set to “thousands” or “millions” of colors . . .«, adhering to a Web-save colour palette
of only 216 colours is no longer necessary to ensure proper page display
in all settings. Nevertheless, a conservative use of colour on Web pages,
as it is advertised by many guideline collections (see, e. g.: Kurniawan &
Zaphiris 2005, p. 131) may actually improve its power as a highlighting
measure. Where a change of colour finds use to encode some form of feedback on user actions, this change needs to be sufficiently intensive, so as to
be easily determinable. This is most relevant for the display of click targets
and will be discussed in detail elsewhere (see subsection 4.2.3).
The material reviewed in the course of this work typically advises against
graphics except for illustrative purposes in direct relation to the textual
content. In keeping with established accessibility standards, graphics should
be equipped with alternative texts or even longer descriptions, as appropriate. Additionally, any informational content encoded in colours must be
accessible in an alternative form. This consideration is obviously not limited
to making pages accessible to elder individuals, but is covered in accessibility requirements addressing the different forms of colour vision impairment.
Various software tools (see, e. g.: Wikipedia, the free encyclopedia 2006a,
External_Links for a listing) are available to access the visibility of Web
pages under various conditions of colour vision and could prove a valuable
tool in identifying any colour-related usability issues.
m
4.1.3 Audio- and Multi-Media Content
The US National Institutes of Health provide a distinct senior health Web
site (NIA & NLM 2006) augmented with synthetic speech output; it reads
the labels of links and buttons when the mouse pointer hovers over them
and content text upon a click on the passage. Apart from such far-reaching
efforts, the importance of audio or audio-visual content as informational
content is very definitely second to text and graphics. Only Holt (2000,
p. 7) comments on the elder-specific aspects of audio content and her suggestions are in line with those already pointed out in section 3.4: presenting
sounds »one at a time« and avoiding background noise or distortions in
47
speech presentations. For multi-medial content, suggestions by Bieri et al.
(2006, p. 21) on the shaping of audio- and audio-visual advertising material apply: rapid sequences, cuts, and parallel presentation of information
are unsuitable for elders. These recommendations draw upon findings on
attention (parallel processing deficits) and information processing as well.
4.2 Facilitate Handling
The title of this section is very nearly figurative language, because the following passages relate mainly to the problem field of intricate movements,
although the section on click targets has a strong visual component as well.
Mouse interactions will be the main point of interest, but typing input on
a computer keyboard may also present some serious difficulties, especially
to those elders new to the world of computers.
4.2.1 Scrolling versus Paging
The question whether scrolling down long pages or clicking through a sequence of several short ones is the best solution to present longer passages
of content has in the past enticed vigorous controversy. The position of the
fold, where the bottom end of the screen cuts off a page that is too long
to display completely in the browser window, is not easily determinable
because it varies with such parameters as display resolution, window size,
typeface, type size, and other system-specific settings on the users’ computers. Depending on the length of the page, this can hide a considerable
portion of the content or functionality of the page. Therefore, particularly
Nielsen has been known to argue strongly in favour of chunking single
long pages into several smaller ones and to avoid the necessity of scrolling
vertically (see, e. g.: Nielsen 1996, Nielsen 1997, Nielsen 2000) as much
as possible. Even though Nielsen (2000, pp. 112/115) acknowledges that
scrolling is a problem especially for pages intended for navigation and not so
severe for pages displaying lengthy text content, the idea that users generally are unlikely to scroll downward still holds considerable sway (see,
e. g.: Becker 2004a, p. 394). Summarising various contributions made on
48
this topic, Wirth (2004, pp. 161–163) points out that there are affirmative
arguments for both paradigms (scrolling as well as paging) and the best
choice very likely depends on the audience, purpose, and content of the
individual Web site. Obviously, the negative or positive effects of scrolling
versus paging can be overcome in various ways. For example, a site could
provide several different views of the same page (e. g. a paginated and a
monolithic variant) and leave the choice to the users—a favourable approach, according to Wirth (2004, p. 165), though it is important to note
that it also increases the number of items displayed on the page and thus
the complexity of the interface. Consider as a possible alternative the hybrid solution proposed by Gustafson (2004).
The reviewed guidelines and research materials generally advise against
the use of scrolling (see, e. g.: Kurniawan & Zaphiris 2005, p. 131) for
several reasons. Gappa & Nordbrock (2004, pp. 83/84) re-emphasise the
“users-do-not-scroll” argument because they observed that the elder users
in their study did indeed often miss information presented below the fold.
Another compelling reason is the requirement of fine motor movement for
controlling the scroll operation. Even a scrolling wheel or a comparable
device, which by now is a standard feature of computer mice and allows the
scrolling with a single finger movement, has been identified as a potential
usability issue with elders (see: Aula 2005, p. 77). Depending on the browser
software, the Up-, Down-, Page-Up-, and Page-Down-keys may allow to
control the scrolling, but they require the users to move from the mouse
to the keyboard as primary interaction device. Without a wheel mouse or
using the keyboard, the users can either click the scroll bar buttons to
scroll down by line, or click and hold the slider and freely move it upor downwards. Hawthorne (2003, p. 41) emphatically criticises that the
above scroll bar elements present tiny targets1 that are by default coloured
in shades of grey and exhibit a default behaviour that may constitute a
source of error and, consequently, frustration to some elder users. Note the
reference to the problem fields of colour and contrast vision. Unfortunately,
the appearance of the scroll bars depends on the settings of the operating
1
the slider becomes smaller when more content is below the fold
49
system and is not reliably customisable through the use of Web technology.
Hawthorne (2003, p. 41) furthermore argues that the movement of the
text in the window, which is the most visible feedback of scroll bar use,
may actually cause confusion in elder users who could loose track of their
position within the page. Because scroll bars appear at the very edge of
the screen in the users’ visual periphery, they might easily be overlooked
(see e. g.: Hawthorne 2003, p. 41). This further strengthens the argument
against scrolling Web pages because a scroll bar alone is a barely visible hint
for further content below the fold. Also, other page elements like horizontal
rules or borders might prematurely suggest that there is no more relevant
content (see: Spool et al. 1999, p. 78). A possible remedy could be dedicated
scrolling buttons (see, e. g.: Badre 2002, p. 102) to facilitate interaction
for elder users. They are larger targets than the standard-issue scroll bar
elements and could also provide additional hints on content hidden beneath
the fold.
4.2.2 ›Seek-and-Hide‹ Menus
For similar reasons already mentioned in the context of scrolling and scroll
bars, many sources (see, e. g.: NIA & NLM 2002, p. 9; Kurniawan & Zaphiris 2005, p. 131) advise against the use, or at least against the extensive
use of menu-like contraptions for Web navigation. This refers to page elements mimicking the functionality of menu bars as typically featured in
computer software where they roll out a list of functions upon a mouse
click. On the Web, such constructions typically display navigation options
when the pointer is above the visible menu element. Like their software
counterparts, they can present a multi-level hierarchy. The labelling of
such constructions as ›Seek-and-Hide‹ menus alludes to their behaviour:
users have to seek out the menu options to see what they contain; the item
lists hide themselves again as soon as the pointer moves away.
Indeed, even in the context of computer applications, the suitability of
such menus for elder users has been called into question (see, e. g.: Ellis
& Kurniawan 2000, p. 273; Hawthorne 2003, p. 40). The main criticism
against menus on the Web, which can be deployed both vertically and
50
horizontally, is again the fine mouse movement necessary to successfully
control them and to select the desired option—especially where multiple
levels of selection, small type for the labels, or both of these factors are involved. Elder users may be unable to hold the mouse steady enough for the
sub-menus to display continuously and due to unsteady movement, hitting
targets may be much more difficult. The standard-issue drop-down fields
provided by HTML, which display only a single element of a list and upon
a single mouse click roll out the alternative options, have faced criticism on
the ground of hiding all but one option in the closed position and offering
only a limited amount of control on the formatting and grouping of the
entries, when employed as a navigation device.
4.2.3 Click Targets
To increase the target size and to give more elaborate feedback on target acquisition were the primary motives to use stylised graphic buttons
(dimensions: 120 × 22 pixels) labelled exclusively with text for the main
navigation in Ellis & Kurniawan’s (2000, p. 271) iterative design experiment. The motives in this case soundly reflect the findings on stimulus
intensity, which detail that in order to detect a difference, elders require
larger changes. Elder users are likely to miss very subtle optical hints and
difficulties with intricate movements call for a distinctive hint of target acquisition. Thanks to advances in Web technology, the initially mentioned
solution can by now be considered obsolete: Appearance changes even for
normal text links can be controlled very elaborately and effects such as
indentation, contrast reversal, typeface and size, colour changes, or within
lists possibly even graphical indicators can be added to make one element
stand out from a group of similar elements or from its immediate background and surroundings. Of course, the arrangement has to maintain
readability in the changed appearance as well and using more than one
of the aforementioned options is advisable for increased effectiveness.
Other observations made by Ellis & Kurniawan (2000, p. 271) teach a
very interesting lesson about white space around click targets: with their
click on a target link, which was part of an unordered list of insufficiently
51
spaced items, the elder users not only failed to hit the link they wanted
to follow, they accidentally hit an adjacent link and thus were taken to a
page they did not expect. Depending on the label and description of the
link, such a mistake may even go unnoticed and thereby cause considerable confusion and frustration. The individual links should appear with a
sufficient amount of white space around them to avoid this problem.
List bullets and carefully chosen, meaningful icons can add to the usability of links, for in their appearance, they often come to resemble buttons.
To further facilitate the navigation for elder users and to reduce the likelihood of error and confusion, Chadwick-Dias et al. (2003, p. 36) recommend
that bullets and icons be incorporated into adjacent links, where applicable;
their participants frequently attempted to click on such elements as well
as other non-links like headings. Because even allegedly obvious iconography like a reading glass for “Search” or a house for “Home page” may not
convey the intended message, Wirth (2004, p. 97) as well as many guideline sets strongly discourage omitting a textual component and employing
icons as links on their own. Without a label, the icon element is bound to
loose size and with that visual saliency; a combination of icon and textual
label has the additional benefit of familiarising the users with the meaning
of the icon and it may thus facilitate recognition on different Web sites
(knowledge transfer).
4.2.4 Input Elements and Keyboard Use
Aula (2005, pp. 75–76) reports on various observed difficulties elder users
had with the text-editing elements of a search interface: laborious text
typing, lost input due to typing while the focus was not in the text input
element, frequent typing errors, difficulties in correcting typing errors, in
positioning the caret, and in deleting old queries. All of these observations
directly relate to the problem field of intricate movement and are relevant
for designing input forms for other purposes than search.
To remedy these problems, Aula (2005, p. 76) asks for a distinct »clear
search box« button to be provided as well as larger type size and enhanced
visual or audio feedback indicating the presence or absence of the input
52
focus in text input elements. A larger typeface here addresses not only
visual acuity deficits: if the single characters are larger, it is easier to position the caret between them. With present-day Web technologies at least,
the typeface and size in text input elements can be modified normally and
the elements should also scale accordingly to accommodate the intended
number of characters. Adding an auditory cue for “unfocussed” typing may
be an issue best addressed at the level of the browser software, although
Web-based solutions are probably possible, too. Furthermore, it may be
advisable to break larger forms into logical units and present them sequentially. Because typing may be a tedious task for elder users, especially if
they are unfamiliar with keyboards, typed text should not be lost when
the user switches between screens in such sequences.
4.3 Reduce the Likelihood of Distraction
Advertisements are doubtlessly distractions of the purest form and many
Web sites that offer free services use them for financial reasons. Advertisements embedded into pages alongside normal elements such as navigation
or content as well as graphic ornaments are, essentially, distractions in a
display that has to be visually searched. They can also have considerable
impact on the amount of time needed to load a page. In a broader interpretation of the term, distractions occur also in the course of normal Web site
navigation. The following passages will assess findings on different forms of
distractions users may have to face on the Web and also point out possible
ways to make Web browsing with distractions easier for elder users, who
are particularly susceptible to their negative influence.
4.3.1 Advertisements
Although animation can have illustrative applications, it is most commonly
used on the Web to embellish advertisements. Wirth (2004, pp. 130–131)
underscores the negative effect non-illustrative moving items can have on
users, quite regardless of the recipient’s age; he argues that persistent movement will disrupt any individual’s concentration, because it has the high-
53
est priority for the allocation of attention. The fact that parallel tasks
present elder users with increasing difficulty emphasises the ensuing difficulty even more. Therefore, elder users should benefit excessively from sites
that choose to abstain from using animated advertisements altogether. If
possible, static or solely text-based ads are to be preferred, if their display
is necessary for financial reasons.
Web advertisements are likely to be more effective when they are displayed interspersed with content at irregular locations or in formatting akin
to navigation elements. They are also, however, much harder to distinguish
from relevant page content. Accessing the relevance of a visual stimulus has
been shown to take elder users longer. Thus, the above-mentioned practise
inconveniences elder users more severely than younger users. In fact, this
is the inverse of the possible compensation strategy already mentioned in
section 3.4. Most authors specifically advise to consistently place advertisements in the page margin only, as their appearance in the periphery can
make their presence less invasive (see, e. g.: Badre 2002, p. 92), and argue
in favour of clear and consistent formatting and placement of links and
navigation elements. Placing the advertisements of a Web site consistently
in a certain area can act as a location cue in that the actual site navigation
and content will appear elsewhere on the screen (e. g. everywhere but at
the left page margin). Observations made in the study by Chadwick-Dias
et al. (2003, p. 34) suggest that not including a right-margin advertisement
space in the minimal dimensions of a page (the minimum screen resolution
or window size at which the page displays without horizontal scroll bars),
can allow the users to see the page without any distracting advertisements,
for the test users in the study were often not aware of the additional content in windows with horizontal scroll bars. However, horizontal scroll bars
are usually considered a major design flaw and the benefits of such practise
obviously depend too much on the configuration of the users’ computers
to constitute a reliable strategy to reduce the distracting effects of advertisements.
A very interesting alternative to traditional Web advertisements could be
to offer access to the more elaborate services of a Web site after the user has
54
watched a short commercial. How the commercial presents the message to
the audience could be varied according to the clients’ needs and preferences
as well as the bandwidth and multi-media capacities of the user’s browser
software. An example for this approach can be seen at the Merriam-Webster
Online Web site (Merriam-Webster Inc. 2006), which offers free access to its
normally restricted services after a flash presentation or a timed slide show
of static graphics. Afterwards, the screen does not contain any advertising.
Presenting advertisements in this manner allows users to stay in control
of their actions. They can also deal with advertisements and the target
Web site sequentially, thereby ridding themselves of the otherwise necessary
parallel processing effort for Web pages containing ads.
4.3.2 Ornamentation
Many of the reviewed sources on elder-specific Web design encourage modesty in the decorative application of colour, graphics or multi-media effects.
The over-enthusiastic use of colour or graphic measures to visually highlight
important information threatens the effectiveness of such measures and increases the complexity of the display, thus making visual searches more
difficult. As already discussed in the context of advertisements, animation
has considerable potential for drawing attention and should therefore not
be present, except if it is informative in nature and directly relating to
the other content of the page. Even then, in the spirit of the recommendation made in section 4.4, they should not start without the users’ informed
consent. As already hinted in the introduction of this section, the likely limitations on the available bandwidth further discourage the excessive use of
ornamental elements of any kind.
4.3.3 Disruptive Navigation
Some navigation options have been identified as particularly confusing especially for elder users. Page-internal links that move downward in a longer
document, possibly by several screen-fulls, may cause the user to loose track
of their position because the page header and regular navigation controls
55
can scroll out of view (see, e. g.: Ellis & Kurniawan 2000, p. 269). For similar reasons, targeting page-internal link targets directly from a different
page, so that following the link displays the link target directly as scrolled
to the corresponding position with the header and navigation controls possibly out of view can be expected to have a similarly disorienting effect on
elder users. This is also an additional argument to favour pagination into a
series of smaller chunks over longer documents with a list of sub-headings
as page-internal targets (see subsection 4.2.1). A slightly different source
of confusion are links referring to the same page in which they appear
(such as a working “Home Page”-link on the home page itself); they may
cause users to look for changes that actually did not happen (see, e. g.:
Chadwick-Dias et al. 2003, p. 34).
4.4 Keep Users in Control
The issues discussed in this section deal with actions carried out by the
browser or system software without being explicitly initiated by the users.
Such actions can take the users out of the context of their immediate
task or require them to deal with a largely unrelated situation. In some
respects, this is reminiscent of the proverbial dog that takes its owner
for a walk. The findings especially from chapter 2 strongly suggest that a
feeling of being in control is particularly helpful for elder users. Unexpected
developments and intrusions should be expected to undermine the users’
confidence in their ability to successfully execute their intended actions.
The following passages address commonly encountered aspects of Web sites
that constitute possible threats to the users’ feeling of control.
4.4.1 External Applications, Downloads, and Plug-Ins
Information in various formats not directly displayable in the browser software is often part of Web sites. Such content requires additional software
to display properly, either within a page, within the browser window, or
by being opened in a new window of external applications, such as a PDF
viewer or player software for sounds, music, or video. Any shortcomings on
56
the user’s side in terms of missing plug-ins or software or even the unexpected opening of such external applications may confront novice and elder
users with severe difficulties and cause confusion—especially if unexpected
additional dialogues, warnings, or error messages ensue (see: Aula 2005,
p. 75). Also doubtlessly confusing are any automatically initiated download processes or redirects to pages from which to download and install
the missing software pieces. Such behaviour confronts the users with the
results of actions they did not approve and thus takes the initiative out of
their hands.
A gentle notice should be supplied for any failed attempts to display
such content within a page, stating what was supposed to be displayed,
why it is not there, and giving very brief instructions on how to fix the
problem. In these circumstances, it might be helpful to point out a swift
way of returning to the page with the embedded content (e. g. to make a
bookmark), because the user would very likely want to see it again with
the additional content enabled. If content requiring external applications
is made available via links, the label and additional descriptions should at
least notify the users that this may open in a different application or result
in a download.
4.4.2 Pop-Ups and New Browser Windows
Opening pop-up windows or new browser windows makes using the Web
unnecessarily difficult for elder users, for they may miss the opening of
a new window altogether and then find themselves wondering why the
cannot get back to the previous page or where the browser controls have
gone (see, e. g.: Chadwick-Dias et al. 2003, p. 37). Some authors report that
occasionally their test users did not notice a transition to a different Web
site. Hence, there are guidelines asking for a warning to be incorporated
into the link, when this is the case. Opening a fresh browser window to
emphasise the following of links to different Web sites is rather too subtle
a hint and doing so breaks the correct functioning of the “Back”-button,
which is basically an undo-mechanism, relatively easy to understand and
quite effective. The management of several application windows has been
57
shown to be a source of difficulty especially for novice elder users (see, e. g.:
Ellis & Kurniawan 2000, p. 271), but the “Back”-button very probably is
one of the prime strategies for this user-group to get back to a known
page on a Web site. With respect to the findings on strategy shifts, the
recommendation clearly is not to open new windows and pop-ups unless
there really is absolutely no other way for a Web-based application to work
properly. In such cases, the links resulting in the new windows or pop-ups
should be labelled accordingly. For example, opening a pop-up window
simply to display a printer-friendly variant of the current page is probably
not necessary. Equipping the printable page with a single link to go exactly
one step backwards does not impede its “printability”.
4.5 Reduce Complexity
As summarised in section 3.4 complexity has been identified as a very
important influence factor for many aspects of cognitive performance. Admittedly, the title of this section is rather imprecise. This merely reflects
the fact that there are also many sources of complexity. Good structure
as well as references to present knowledge have been identified as possible strategies to reduce complexity. The discussion in this section will first
focus on text and language. Afterwards, it moves on to Web site structure and considers complexity with regard to the layout of individual Web
pages. A final passage will comment on the use of site-specific help and
contact features.
4.5.1 Text and Language
With regard to text length on Web pages, Krug (2006, p. 45) coins the very
provocative sentence: »Get rid of half the words on each page, then get rid
of half what’s left.« Although he does not make any assumptions about
the targeted Web audience, the general thrust of his statement appears to
have particular validity for elder Web users. In the first of their consecutive
usability studies, Chadwick-Dias et al. (2003, p. 34) observed a tendency
in their elder participants to read most, sometimes all of the text presented
58
on the screen, especially when they were asked to fill in forms. Even though
the authors did not report whether or not a similar behaviour occurred in
their follow-up study with a modified design and also did not identify a
specific influence factor responsible for this behaviour, their observation
encourages concise writing, nevertheless.
The complexity of text content is a concern investigated by Becker
(2004b, pp. 400–401) in a study of Web-based health information resources;
she suspects that highly complex texts2 may prove a barrier to older adults,
owing to both an age-related decline in text comprehension and the lower
level of formal education. Note that these assumptions provide an interesting counterpoint to the not elder-specific work of Spool et al. (1999,
pp. 70–71), who found that user success was associated with sites that
contain highly complex texts3 . The purpose of the page in question, for example navigation versus a detailed presentation of content, would of course
tremendously influence how concise or complex the text can or should be.
In this respect, a guideline calling for simplicity in the sense of the assessment metrics and small amounts of text on pages at the same time may
constitute a contradiction in itself.
Detailed recommendations regarding composition style should transfer
from other domains such as technical writing to the writing for Web content in general. The reviewed age- and Web-specific material mostly emphasises the need for text clarity. As Bieri et al. (2006, p. 27) conclude for
advertisements and promotional material aimed at elders, messages and
information of textual nature presented to elder users on the Web should
be phrased unambiguously, without the need to make inferences or anticipate the meaning of the message, and should draw on knowledge the user
already has. Extending these suggestions, the NIA & NLM (2002, p. 7)
checklist instructs writers to use positive statements and active voice constructions; both measures work to make sentences easier to understand and
are well-established guidelines for technical writers.
2
3
rated as complex in automatically measured reading complexity metrics
complexity again rated on automatically calculated metrics
59
Without any doubt, however, the use of jargon and unexplained technical terms that elders as well as Internet novices in general are likely
to be unaware of, can be a source of confusion and frustration (see, e. g.:
Chadwick-Dias et al. 2003, p. 34). Without reference to age-specific issues
and addressing the situation for German Web users, Wirth (2004, pp. 58–
59) argues that many words and expressions commonly used on the Web
leave startling percentages of users without any idea as to what they mean;
he presents the word »Sitemap [!]« (unknown to 45 %) as an example for
a term describing something of considerable relevance and potential benefit. Another example given by Wirth (2004, p. 58) relates to many users’
unawareness of the meaning of the expression »Skip Intro« (unknown to
39 %), which is notoriously used to label a link that bypasses the showing of an animated introductory trailer and leads to the actual home page
of a Web site. Similar observations on the use of computer and Internet
terminology occurred to Aula (2005, p. 74), who notes that even for messages presented in the users’ native language, ». . . the meaning . . . was
not understandable . . .«. These illustrations clearly show how seemingly
unobtrusive terms can become potential pitfalls for novice or elder users.
If the use of such terminology is unavoidable, the Web site must provide
easily understandable explanations, possibly by means of a glossary.
4.5.2 Site Structure
Most Web sites can be expected to present their content in some form of
hierarchical structure which might also feature internal cross-references via
links that are not part of the main navigation. With reference to elders,
recommendations exist which call for no more than two hierarchical levels
on a Web site (see: Gappa & Nordbrock 2004, pp. 83/84) or plainly state
»Do not use a deep hierarchy . . .« (Kurniawan & Zaphiris 2005, p. 131).
The background appears to be the increasing anxiety of the elder users of
»getting lost« within the structure of the Web site or loosing track of the
navigation steps already made (Gappa & Nordbrock 2004, p. 83). Suggestions to keep the structure of Web sites shallow, however, are not limited to
elders; consider Rosenfeld & Morville (2002, pp. 67–69), who recommend
60
to generally favour a shallow and broad over a deep and narrow hierarchy and advise to use two or three levels at most. These recommendations
base on research by Larson & Czerwinski (1998, p. 30), who found that
in relatively broad but shallow hierarchies (16 and 32 nodes, 2 levels), the
search performance of the participants was better than in a narrow but
deeper hierarchy (8 options, 3 levels)—results these authors attribute to
the fact that making decisions about navigation options took more time
than a visual search of the display. Interestingly, Larson & Czerwinski
(1998, p. 30) found no correlation between short term memory and search
performance in the narrow-deep hierarchy assessments, as opposed to their
other settings, where both memory and visual search ability were relevant
influences.
Based on their own experimemts, Gappa & Nordbrock (2004, p. 84) also
recommend limiting the main navigation options on a page to six which,
they acknowledge, can come into conflict with their other recommendation
of avoiding hierarchies with more than two levels. Conflicting, as these notions may be, they soundly reflect that age-related deficits may be present
in both visual searching ability and memory. Limiting the organisation of
a Web site in this manner is not always possible; larger Web sites often
require more hierarchy levels to organise their content and problems regarding navigation also manifest in the development process as well, as
can be concluded from Krug’s (2006, p. 70) remarks that material delivered for usability evaluation often contains site charts showing a four-tier
hierarchy and design samples for the home page and navigation and content pages for the first two levels. These comments nicely commemorate
the problem that occurs after the first two levels of a hierarchy have been
incorporated into the Web site navigation: a Web page has only two natural directions along which category listings might be displayed easily; these
are from left to right and from top to bottom.4 Afterwards, some form of
aggregation is necessary to accommodate all navigation options, for example in a “Windows-Explorer”-like tree navigation, and showing too many
sub-nodes may easily result in cluttered displays. For such deeper hierar4
Note that for non-western Web sites, other conventions such as right-to-left may apply.
61
chies, Bernard (2003) recommends a concave hierarchy: a larger number of
options at the top and bottom level of the structure and fewer choices in
between.
The organisational dilemma described in the initial paragraph remains
largely unsolvable except for small Web sites with limited amounts of content, where such considerations are of less immediate relevance. The observations made with regard to elder-specific usability issues, however, highlight the importance of both devising a carefully organised structure and
presenting it in a way that prevents the users from being overwhelmed by
choices and getting lost.
4.5.3 Page Layout
A very well-established design fundamental is using various visual cues
available to construct a meaningful visual hierarchy that can effectively
guide the users’ attention to the information or functionality they are looking for. In keeping with research findings on attention and location cuing,
guidelines for elder-friendly Web design strongly emphasise the importance
of layout simplicity and spatial consistency: the consistent placement of interface elements on all pages, throughout the Web site.
The wording usually refers directly to navigational elements, but a clear
and above all predictable visual alignment of page elements in general certainly improves the usability of the site especially for elder or novice users,
because it facilitates the transfer of acquired knowledge (see, e. g.: Nayak
et al. 2006, p. 8). This remark has not only site-internal scope, but applies
also to knowledge acquired on the Web in general. Thus, honouring wellestablished Web conventions regarding the placement of page elements will
allow all users to continue using well-learned strategies. The use of elaborate content management systems for most larger Web sites usually ensures
that at least navigation elements appear in a consistent form and placement. Using a page layout on a home page that is significantly different
from the rest of the Web site (see, e. g.: Krug 2006, pp. 107–109), for example by displaying a horizontal navigation bar for the main site categories
on the home page and a vertical navigation bar on the left margin every-
62
where else, may not be advisable, as this layout change can cause confusion,
especially if the labelling is inconsistent as well.
For reasons already discussed in subsection 4.2.1 on problems with Web
pages that require scrolling, placing any important or potentially helpful
page elements (e. g. utilities to resize the text, to print, to access the search
or contact information) below the fold or even at the bottom of the page
should be considered a remarkably bad idea. The place for such elements
is most certainly within the header where they are prominently visible at
all but the tiniest window sizes and also directly available.
4.5.4 Help and Contact
Some of the reviewed guideline sets (see: Holt 2000, p. 5; Kurniawan &
Zaphiris 2005, p. 131) recommend dedicated help pages and a collection
of frequently asked questions5 to cover problems with the Web site itself
as well as with the provided content, products, or services. The idea of
providing instructions or even a manual on how to use an individual Web
site may to some appear as somewhat contrary to usage strategies commonly applied on the Web (see e. g.: Krug 2006, p. 26). Nevertheless, such
practice may help to reduce the user’s uncertainty, according to Singh &
Pereira (2005, pp. 100–101) who bring up such site-specific tutorials in the
context of cultural and national differences in Web usage. A possible form
for such endeavours is characterised by Rosenfeld & Morville (2002, p. 126)
as ». . . guided tours, tutorials, and micro-portals focussed around a specific
audience, topic, or task.«
Providing information on how to contact the entity behind a site is in
the best interest of the owner and also, to some extent, a legal requirement.
Elder users, as has been discussed in chapter 2, might be quite willing to
look for information on-line, but some may prefer to conduct transactions
“with real people” outside the Internet and would probably appreciate
a prominently visibly opportunity of contacting a real person or doing
enquiries in a way they prefer (e. g. by e-mail, telephone, fax, or mail).
5
typically labelled just with the acronym FAQ
63
4.6 Provide a Sound Base for Navigation Decisions
On Web sites, successful navigation is the key to reaching the desired information. Therefore, usable navigation elements are of paramount importance for user satisfaction (see: Nayak et al. 2006, p. 8). Metaphors from the
real world have frequently found use in computer and information technology to tap into the existing knowledge of users and thereby to facilitate the
understanding of the technology. Metaphors might be employed to mimic
the behaviour of real world items or to organise information. For example, the quite literal human resource office metaphor implemented in the
experiment described by Gourmelon (1994, pp. 187–189) manages to effectively hide the complexity of the underlying computer system and taps
the domain-specific knowledge of the intended user group. To maintain a
universally accessible Web site, however, only general knowledge can be
considered a reliable resource for suitable interface metaphors. Still, some
elements known from established media, most notably from printed media
like books, magazines, or newspapers can offer useful inspirations and also
might be helpful in overcoming some of the naming difficulties uncovered
previously. This can be particularly helpful for several navigation tools relating to a Web site in general, which have been identified as valuable aids
to elder users by facilitating navigation and information finding. The first
subsection discusses how such tools and different navigation paradigms can
address the requirements of elder users. The second subsection then reviews
findings on the smallest possible navigation element, the individual link,
and especially its labelling.
4.6.1 Navigation Paradigms and Tools
Numerous paradigms exist to present the main navigation options of a Web
site. One of the most successful, if well designed, is the tab set6 ; many sites
use the tab metaphor to present their main information categories, often in
combination with colour coding (see: Krug 2006, p. 79). Most elder-specific
guidelines reviewed here do not specifically endorse a distinct way to im6
as known from filing cabinets
64
plement the navigation, but they give rationales against some, which have
been discussed in subsection 4.2.2. Kurniawan & Zaphiris (2005, p. 131),
however, include a guideline specifically asking for links to appear in a
bullet list. Present-day Web technologies can customise the appearance of
such lists and their items to a remarkable degree, and the result manages
to simultaneously mark-up the list content correctly (important with regard to accessibility for non-visual Web browsing devices) and display it
in a visually appealing manner, for example in the form of a tab set or a
vertical navigation bar. For the vertical displays, it is advisable to have the
entries preceded by some form of bullet or indicator to make them identifiable as distinct entries even when they have been wrapped across more
than one line. Chadwick-Dias et al. (2003, pp. 34/36) also emphasise the
importance of clearly indicating the presently selected item in the navigation system. In line with the statements in subsection 4.2.3, more than one
cue should be used for this. For deeply hierarchical Web sites, the use of a
Breadcrumb-device, which displays links to the superior pages, is also very
advisable to provide an additional cue about the present position on the
Web site.
For functions that require user input, Dickinson et al. (2005, p. 627)
have found in the course of their development project that even long linear navigation paths with specific instructions displayed on each step page
are a feasible solution for elder users. They acknowledge, however, that
such an approach is suitable only for specific actions that can be broken
down into a predictable sequence of smaller steps. When doing so, however, accompanying each step with instructions detailing the purpose of
the sequence, the steps already done, the purpose of the current step, and
the remaining steps in the sequence would help elder users to keep track of
their activity. A very good example for this type of navigation is the order
processing in an electronic shop, where the customer reviews the list of
items in the shopping cart, provides information about delivery and payment, and finally proceeds to acknowledge the order placement. The NIA
& NLM (2002, p. 10) checklist explicitly advocates the incorporation of
“Previous page”- and “Next page”-buttons, which obviously make sense
65
within a sequence of pages only7 . Defining such a sequence for an entire
Web site is seldom feasible, but at the lowest levels in information hierarchies with three or more tiers, where the individual pages probably are
closely related, it could be an alternative to including yet another subset
of links in the main navigation system.
Nayak et al. (2006, p. 8) recommend to always provide a prominently
visible link to the home page of a Web site. Apart from any such functionality already incorporated into a logo, a dedicated link would offer an
escape route to “lost” users with an option of returning to a known page
and would usefully complement the functionality of the “Back”-button.
This is especially true for situations in which going one step backwards
is not a viable solution, for example when the result of a Web search led
directly to a lower-tier page of a Web site.
One of the most important navigation tools, especially on larger Web
sites, is a site-wide search facility. The participants in Gappa & Nordbrock’s
(2004, p. 83) study often turned to the search box, some after they had not
obtained the requested information by other means, some directly as the
primary solution strategy—a finding which emphasises the importance of
well-designed search facilities. Elder users may encounter unique problems
when dealing with search engines or site-wide search functions, some of
which were already discussed in subsection 4.2.4. Aula (2005, p. 77) notices
structural difficulties such as understanding the scope of a search function
(e. g. search this site versus search the Web) or dealing with the result
display. Gappa & Nordbrock (2004, p. 84) also make detailed suggestions
regarding the query handling: forgive spelling mistakes, accept declined
nouns or conjugated verbs and suggest synonyms based on previous queries.
Supplying a history of previously entered queries could also be a way to
improve the handling of search facilities for elder users.
According to Gappa & Nordbrock (2004, p. 84), especially the elder users
in their study tried to transfer their knowledge of printed media and employ according search strategies like browsing from an index. This directly
7
with the possible exception of “Previous page”, which could also simply go one step
back, just like the “Back”-button of the browser software.
66
points towards two auxiliary structures borrowed from printed media that
might form a valuable alternative or complement to traditional search facilities: the Table of Contents and the Index. According to Rosenfeld &
Morville (2002, pp. 121–122), the term Table of Contents was the original label used for site maps. Although some site maps do indeed deliver
a map-like representation of their Web sites, the most common form is
simply a structured listing of links to the main and subordinate sections.
Site maps receive praise for providing a good overview of the contents of a
Web site and direct access to information; they are usually named as very
valuable navigation aids especially for elder users (see, e. g.: NIA & NLM
2002, p. 10; Kurniawan & Zaphiris 2005, p. 131). Depending on the nature
and purpose of the Web site, a contrivance modelled after indices found
in printed media (see, e. g.: Rosenfeld & Morville 2002, pp. 123–125) could
also facilitate direct access to information through sorted keywords from
various domains, (e. g. author, subject, location, or other categories as suitable), thereby bypassing the hierarchical structure. An Index represents a
relatively simple and strictly linear search space and should thus be intuitively usable for elder users. As Rosenfeld & Morville (2002, p. 123) state,
an index alone might be sufficient for smaller Web sites, whereas larger
structures would likely require site maps and search functions additionally.
Finally, a noticeably different marking for visited links to make them
distinguishable from unvisited links provides a valuable memory cue for
elder users and the reviewed guideline literature frequently advises such
marking. It is possible to maintain several different colour schemes for
links, either to make them more readable within the overall page design, or
to convey additional information about the links nature. An example is the
application of different colours to links within the displayed page, to other
pages within the same Web site, or to different Web sites altogether. There
are no established customs for such coloured markings, however, and thus
any attempt to introduce one would probably require a legend to explain
the meaning. Not all links, however, need to incorporate the “visited”feedback; for purely functional elements such links to access a site-wide
functionality (e. g. the search, shopping cart, changing the type size) or
67
links continuing or backtracking a pre-defined sequence of steps, graphic
buttons or icons with accompanying text may even be more efficient.
4.6.2 Link Labelling
Displaying links with a sufficiently descriptive label that allows users to
foresee what kind of content it leads to is not necessarily a requirement for
elder users only. Spool et al. (1999, p. 33) determined two essential success
criteria for links in their study: a link must allow users to ». . . predict where
. . . [it] will lead« and to ». . . differentiate . . . [it] from other, nearby links.«
Adding a short textual description for links that are otherwise unclearly
labelled, proved to be a valuable hint on which users could base their
navigation decisions (see: Spool et al. 1999, pp. 35–36). Based on experience
with their model for the computational evaluation of Web site architecture,
Miller & Remington (2004, p. 216) argue that the quality of the link labels,
the degree of their ambiguity, very likely exerts a greater influence on the
search performance in multi-tiered Web site hierarchies than the number
of levels. With respect to the findings on problem-solving and decisionmaking, it is reasonable to assume that the low quality of links in terms of
the criteria mentioned above will be particularly hindering for elder users.
Present-day Web technologies offer various ways of displaying additional
information not only for links, but for many other objects on Web pages
by using the title-attribute. As a result of supplying such a title, a tool
tip appears when the pointer hovers above the titled object. Hawthorne
(2003, pp. 41–42) raises a number of valid concerns against the standard
tool tip behaviour, such as unreadably minuscule type, unexpected and
thus disruptive appearance, or obscuring the view of the controls below
the hint. Hawthorne introduced a number of customisations on the level
of the operating system to remedy these effects, but for Web pages, such
solutions are hardly feasible. The accepted solution in Ellis & Kurniawan’s
(2000, p. 271) experiment was based on hidden layers containing further
descriptive text and made visible when the pointer touched the navigation
buttons. The most easily available solution to this problem, however, would
be a longer link label or a permanently visible descriptive sentence.
68
Apart from the global requirement of consistent terminology, there are
some recommendations on the wording of link labels. Drawing on observations made in the course of their studies, Chadwick-Dias et al. (2003,
pp. 36/33) advise the use of »Action Word Links«, which presumably
caused their participants to overcome the »Cautious Clicking«-behaviour
exhibited in the baseline study. Essentially, this recommendation corresponds to the points made initially regarding descriptiveness, for the authors say that ». . . older adults . . . are much more likely to click links that
explicitly tell them what will happen when they click« (Chadwick-Dias
et al. 2003, p. 36). Pre-study evaluation results prompted Dickinson et al.
(2005, p. 626) to reconsider the labelling of the buttons and links in their
application: »Terms like “my home page” were removed because of uncertainty about who “my” referred to.«8 Instead, addressing the user directly
in the third person appears to be a sufficiently clear alternative.
Using the actual heading of a Web page as the label of the link leading to
it and presenting this heading so that it makes the page easily identifiable
is another example of a guideline well established aside from any agerelated considerations (see, e. g.: Badre 2002, p. 136). Doing so promotes
consistency, as both the labels and the headings can be generated from the
same source; this practice also provides an immediate control mechanism
for the users, as to where they are and whether they followed the correct
link. Note, however, that the page heading is not automatically the page
title, which appears in the title bar of the browser window and will be used
as the caption for any bookmarks made from a page. Including both the
name of the Web site and the main heading of a page in its title would
therefore provide a valuable memory cue to facilitate recognition in the
browser bookmark list.
Particularly on Web sites catering to audiences whose native language
is not English, it is important to use understandable labelling for all navigation and function elements. For the “metaphorical” tools introduced in
the previous subsection (site map and index), reverting their labels to the
8
Consider also, however, the clarity of the term “home page”, especially for novice
users or those without any command of the English language.
69
local equivalent of Table of Contents and Index should greatly promote
easy understanding and improve the usability by giving all users a clear
idea of what to expect. Appropriate labels on German Web sites would be
Inhaltsverzeichnis and Stichwortverzeichnis. It is at least doubtable that
elder users would notice the potential helpfulness of these tools for navigating a Web site if the were to retain their Web-specific names.
4.7 Examples from the Web
In this section, comments on a number of Web pages will serve as illustrations for some of the recommendations made in this chapter. They were
chosen from Web sites likely to be within the sphere of interest of elder Web
users, according to the findings in section 2.1. The comments are certainly
not exhaustive, but they do show that a number of usability issues can be
uncovered through application of the principles developed in this chapter.
They also show that the problems identified in the course of this work do
have their manifestations on the Web despite advances in technology and
efforts to make information universally accessible. The screen shots given
within the text are monochrome only and some may be too long to fit on
a single page at a reasonable size. Appendix B. reprints all screen shots in
colour and also supplies the full-length images, scaled to height.
4.7.1 News: spiegel.de
The Web site depicted in Figure 4.1 uses a static layout optimised in width
for a display resolution of 800 × 600 pixels. At that display setting, the
vertical banner advertisement would not be visible. The main point of
criticism in this example bases on the recommendations made in section 4.3
under the heading of ›Reduce the Likelihood of Distraction‹. Consider, the
text-based advertisements in right column, directly adjacent to the column
with the main articles. They bear a striking similarity to other elements
with actual content in that column because they employ the very same
formatting for their links. The top-most ad at least could easily be mistaken
for a normal article, despite the different background colours for these ads
70
http://www.spiegel.de/wirtschaft/
Screenshot at 1024 × 786 display resolution. Retrieved 11 July 2006, 23:30 UTC+1 with Microsoft Internet Explorer 6.
Figure 4.1: The economy section on the Web site of Spiegel Online. The
black box indicates the approximate view on a 800 × 600 display, the line
indicates the approximate position of the fold at 1024 × 786. See Appendix
B.1. for a colour plate.
(not the same for all, though) and the designation Anzeige (advertisement)
in the top-right corner, which are the only markings applied to this kind
of advertisement. These text-based ads as well as small flash-based ones
occasionally appear within the text of articles, too. With respect to the
recommendations from section 4.2 and section 4.5, the remarkable length
of the page also inspire negative comment (see Appendix B.1. for the fulllength version).
71
http://www.docmorris.de/
Figure 4.2: The home page of the DocMorris Internet pharmacy. The
black lines indicate the apprpximate position of the fold at resolutions of
800 × 600 and 1024 × 786 pixels. See Appendix B.2. for a colour plate.
4.7.2 On-line Pharmacy: docmorris.de
The home page displayed in Figure 4.2 belongs to an Internet pharmacy
based in Holland. At a first glance, it appears to be reasonably well suited
for elder users: the controls are generously sized and the main intentions
users are likely to have are prominently addressed and labelled with verbs.
Thus, the site does relatively well, especially with regard to ›Facilitating
Perception‹ (section 4.1) and ›Provide a Sound Base for Navigation Decisions‹ (section 4.6). Still, there are some minor points to be made for
72
each. The text resizing option resides well below the fold at a display resolution of 800 × 600 and also at the more generous 1024 × 786 pixels. The
telephone number for direct contact to service staff is below the fold as
well and the home page itself does not appear in the tab set used as the
main navigation. There is a home page link, commendably labelled in plain
German (Startseite), but it is rather small and does not convey the information that this is, in fact, the home page. Likewise labelled in German
but also rather too small is the link to the site map in the top-left corner
(Übersicht). As explained earlier in subsection 4.6.1, the German word for
Table of Contents may be a better label to describe the functionality because Übersicht (overview) is rather vague. Unclear terminology appears
also in the text below the search function (the acronym PZN ) and in the
tab link to DocMorris’ on-line shop. In keeping with the notion on action
word links, it could be labelled Einkaufen (go shopping).
4.7.3 Travel: bad-sassendorf.de
Tourism based especially on elaborate health and spa facilities is a main
charactaristic of the German town Bad Sassendorf. A page from the lowest level of the Web site hierarchy appears in Figure 4.3. In this case, the
main concerns are about the ›Facilitate Handling‹ (section 4.2) and ›Reduce Complexity‹ (section 4.5) recommendations, but some comments also
concern ›Facilitate Perception‹ (section 4.1). Although it is not directly evident from the screen shot, the Web site employs colour coding for its main
sections. All the surfaces shown in shades of yellow (see Appendix B.3.)
change to shades of green, blue, violet, or other colours, depending on the
selection made in the menu bar on the right. As a result, the colour change
is very well noticeable, but it always affects all the navigation tabs and
thus is not connected to the specific sections in the menu bar at all. The
type size used throughout the site is also very small and not amendable to
browser-side resizing9 . There is no possibility to change the type size on the
site itself. Furthermore, the menu bar resides at the right, instead of the
9
It does not respond to resizing in Microsoft Internet Explorer 6. Other browser software may use a different resizing technique.
73
http://www.bad-sassendorf.de/generator.aspx/templateId=
renderPage/id=3576.html
Figure 4.3: A third-level page from the Web site of Bad Sassendorf. The
black line indicates the approximate position of the fold at a resolution of
800 × 600 pixels. See Appendix B.3. for a colour plate.
well-established left side, offers no feedback on target capture other than
the change of the pointer, and the colour change indicating the presently
selected menu item is very subtle indeed, especially for the less saturated
colours employed in the design. The breadcrumb navigation, which could
provide valuable feedback about the current position on the site, resides
below the fold as do the search function and the print button. The icons
at the top offer helpful navigation options in a prominently visible position and are all equipped with text labels. These labels, however, contain
Internet terminology: Home and Sitemap).
4.7.4 Public Authority: kreis-recklinghausen.de
The home page of the German district Recklinghausen (Figure 4.4) offers
access to information, forms, and services provided by the local authori-
74
http://www.kreis-recklinghausen.de/
Screenshot at 1024 × 786 display resolution. Retrieved 11 July 2006, 16:43 UTC+1 with Mozilla Firefox 1.5.
Figure 4.4: The home page of the German district Recklinghausen. The
black line indicates the position of the fold at a display resolution of 1024×
786 pixels. See Appendix B.4. for a colour plate.
ties. It uses frames to display a vertical set of always present links at the
left border and a header at the top. The most important grievances on
this site once more are covered under the heading of ›Facilitate Handling‹
(section 4.2), with references also to ›Facilitate Perception‹ (section 4.1),
›Keep the Users in Control‹ (section 4.4), and ›Provide a Sound Base for
Navigation Decisions‹ (section 4.6).
The leftmost frame offers no scroll bar even if its contents disappear
below the fold due to window size or screen resolution. On the author’s
machine, the four links at the bottom were inaccessible at a resolution of
800×600 pixels. This is particularly vexing because among the endangered
links are the ones titled Home and Email. The ›Seek-and-Hide‹ menu bar
75
at the top of the main content frame will follow any scroll movements and
it thus remains accessible at all times. It displays up to three levels of the
Web site hierarchy. The item lists of the menu do not display their labels
in a colour combination that offers very high contrast, for they appear in
blue text on a blueish background. Some of the links in the menu leave the
Web site without any prior notice and also open a fresh browser window
in the process. A help option does appear at the utmost right in the menu
bar and it reveals, among other items, links to a collection of frequently
asked questions and to a site map, which could be put to much better use,
were they permanently visible and, in the case of the site map, equipped
with more descriptive labels.
The navigation system on this Web site does not give any feedback about
the current position in the structure. The links in the centre all open new
browser windows and many, but not all of them have a warning incorporated into their label, which in itself usually conveys no information
whatsoever about the target but relies solely on the preceding unlinked
text. Many of the links not only open new windows but also lead to documents in the PDF format, possibly launching another application. Finally,
the button to trigger the search function is rather small and would likely
present a challenging target to many elder users.
76
5 Final Remarks
This work used a tripartite approach to explore the context of elders,
ageing, and Web usability. The first part was aimed at the sentiment of
technology scepticism among seniors and identified possible causes on the
grounds of mainly social influences on the process of technology adoption.
The second part then assembled information about human ageing and its
consequences for normal Human–Computer interaction. These considerations provided the basis for the formulation of six basic recommendations
as a result of an exploration of existing Web usability guidelines and relevant research. The following passages will revisit each of the main topics
in reversed order of appearance.
The recommendations made in chapter 4 aggregate what appear to be
the most important guidelines to address difficulties that especially elder
users are likely to experience. They can probably help to uncover usability
issues of special relevance to this user group, but the examples employed for
illustrative purposes do not, off course, constitute a full-scale evaluation.
5.1 Conflicts and Inspirations
The recommendations are not without conflict. Type size, for example, is a
field of tension: A larger base type size often means longer pages. The need
for scrolling, as has been noted by Chadwick-Dias et al. (2003, p. 36), may
offset any positive effects of a larger type size. Indeed, the need for scrolling
in itself constitutes a handling problem and the recommendations made in
section 4.2 advise to avoid it if there is a sane alternative. A case of outright contradiction is the structural dilemma described in subsection 4.5.2:
limiting the number of options visible and at the same time the number of
hierarchical levels in the Web site structure.
77
5 Final Remarks
Even more salient is the impact of the various strategies to counter agerelated difficulties that have found their way into the recommendations.
They typically address problems that are common to many, if not all Web
sites and in some cases, a site-per-site implementation may even duplicate already present browser-side functionality. Even when elder users were
aware of potentially beneficial browser-side functionality like type size controls or colour settings, they have been observed to be somewhat reluctant
to use them, even if such features might make using the Web easier (see:
Ellis & Kurniawan 2000, p. 273). Offering the programme functionality in
the form of simple tool bars with enlarged buttons, each containing an
icon and a label, is suitable for a limited amount of functionality, but as
Hawthorne (2003, p. 40) concludes ». . . it would not scale up to a more
complex application«, the configuration of which is beyond many novice
users anyway. Individually providing the functionality on Web sites cannot
be the final solution to this problem because it would mean additional options displayed on the Web pages, less space for the intended content, and
ultimately increasing complexity, which should actually be reduced, as has
been captured in section 4.5.
These conflicts may, however, serve as inspirations for future improvements, especially of the browser software. The most obvious starting point
would be offering the most important and useful features as labelled tool
bar buttons by default. Suitable examples are a site- or time-specific history, the page-internal search, and especially text resizing and colour preference options. This would allow the removal of redundant features and
controls from both browsers and Web pages and could help to simplify the
interface finally presented to the Web users. Furthermore, enhancing the
“internal” communication of Web site and browser software in order to rid
the users of tedious but necessary tasks and thereby promoting usability
for all users should be an interesting line of future development. Automatic
language selection is, perhaps, a start, but there is potential for further integration, because many aspects of Web browsing do not concern only a
single Web site.
78
5 Final Remarks
5.2 Ageing
The assessment of age-related change of mind and body revealed numerous
problem fields and the recommendations in chapter 4 try to address them.
It is important to remember, however, that ageing is not a disease, and it
does not necessarily bring debilitating change with it. A uniform finding of
ageing research, at least in the cognitive branch, is the increasing diversity
of the results, and many factors have been shown to influence the extend
of age-related decline, most notably physical health and fitness. Possibly,
societal changes will also effect the manifestation of the ageing process.
Still, some changes are a very likely natural accompaniment of this ageing
process and also, as of now, irreversible. The most notable examples are
the changes in visual perception (in acuity, contrast and colour vision)
and particularly the loss of the ability to accommodate for near vision.
Product design in general, not only Web design, will have to address these
and other requirements in design in order to avoid excluding a growing
number of human beings.
5.3 Technological Innovation as a Social Process
From the examination of the “Senior-Individual–Internet” relation, the
central finding, perhaps, is that there is a multitude of factors responsible for an individual’s interest in and attitude towards technology. Many
of these factors originate in human society and thus are subject to change
over time. In the near future, so much is certain, the age gap in Internet
usage as described in chapter 2 will vanish, but others will not (yet). For
Internet usage, other divides exist and may continue to do so for some
time along the gender or education borders. Ultimately, they may simply
be a question of socio-economic status before using the Internet comes as
naturally as using a telephone. Some of the factors identified as possible
causes for the age gap, for example the lack of ›ability confidence‹, which
is probably a by-product of the general societal attitude towards ageing
and the aged, may take a longer time to change.
79
Appendix
A. Logitech e-mail correspondence
A.1. Inquiry Text
I understand that some time ago, Logitech offered computer
mouse with force feedback feature. I also heard about mice
that used or were to use various patterns of vibration in
order to give some impression of the haptic quality of
whatever was under the pointer (e.g. window borders, panels,
and similar), branded as "iFeel".
As apparently none of these are presently in your range of
products, I concluded that your company must have discounted
the approach of force feedback mice for some reason. If
this assumption is correct, I would like to know, why these
products were discontinued.
A.2. Answer
Betreff:
IFeel mouse [Incident: 060320-001233]
Von:
"Logitech EMEA Support"
<logitech_support_en@mailca.custhelp.com>
Datum:
Mon, 20 Mar 2006 19:11:08 +0100 (CET)
An:
kal@uni-paderborn.de
80
Appendix
Recently you requested personal assistance from our on-line
support center. Below is a summary of your request and our
response.
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Subject
IFeel mouse
Discussion Thread
Response (Percy König) 20/03/2006 07.11 PM
Sehr geehrter Herr Lohr!
Vielen Dank für Ihre Anfrage.
Wie ich Ihrer E-Mail entnehme, haben Sie Fragen zur den
iFeel-Mäusen.
Logitech untersucht immer in neue Formen der Eingabegeräte
und deshalb hatten wir in der Vergangenheit auch Mäuse, die
81
Appendix
ein Feedback über Vibration zum Benutzer wiedergaben. Diese
Technik hat aber nicht Erfolg am Markt gehabt, sodass wir
diese Art von Eingabegeräten nicht weiter entwickelt haben.
Dies war eine Kooperation mit der Firma Immersion. Unter
deren Website http://www.immersion.com können Sie viele
Informationen zu diesem Thema finden.
Viele Fragen werden in unseren FAQs
http://logitech-de-emea.custhelp.com beantwortet. Ich helfe
auch gerne per E-Mail weiter.
Mit freundlichen Grüßen
Percy König
Logitech Europe SA
European Customer Service
Question Reference No060320-001233
Product Level 1:
Logitech
Product Level 2:
Pointing Devices
Product Level 3:
iFeel Mouse
Date Created:
20/03/2006 02.22 PM
Last Updated:
20/03/2006 07.11 PM
Status:
Solved
Modellnummer:
Teilenummer:
Betriebssystem:
Software Version:
Computer Marke:
Ihr Händler:
82
Appendix
B. Screenshots
B.1. spiegel.de
83
Appendix
84
Appendix
B.2. docmorris.de
85
Appendix
B.3. bad-sassendorf.de
86
Appendix
B.4. kreis-recklinghausen.de
87
Appendix
88
Bibliography
Aula, A. (2005), ‘User study on older adults’ use of the Web and search
engines’, Universal Access in the Information Society 4, 67–81.
Backes, G. M. & Clemens, W. (2003), Lebensphase Alter: eine Einführung
in die sozialwissenschaftliche Alternsforschung, Grundlagentexte
Soziologie, Juventa Verlag, Weinheim.
Badre, A. N. (2002), Shaping Web Usability: Interaction Design in
Context, Addison-Wesley, Boston, San Francisco, New York.
Bayles, K. & Kaszniak, A. W. (1987), Communication and Cognition in
Normal Aging and Dementia, Taylor & Francis, London.
Becker, H., Eichenseer, C., Becker, U. et al. (1991), Die Älteren: zur
Lebenssituation der 55- bis 70jährigen; eine Studie der Institute
Infratest Sozialforschung, Sinus und Horst Becker, Reihe Praktische
Demokratie, Verlag J. H. W. Dietz Nachf., Bonn.
Becker, S. A. (2004a), ‘E-Government Visual Accessibility for Older
Adult Users’, Social Science Computer Review 22(1), 11–23.
Becker, S. A. (2004b), ‘A Study of Web Usability for Older Adults
Seeking Online Health Resources’, ACM Transactions on
Computer–Human Interaction 11(4), 387–406.
Beier, B. & Vaughan, M. W. (2003), The Bull’s-Eye: A Framework for
Web Application User Interface Design Guidelines, in ‘CHI ’03:
Proceedings of the SIGCHI conference on Human factors in
computing systems’, ACM Press, New York, pp. 489–496.
89
Bibliography
Bernard, M. L. (2003), ‘Optimal Web Design: How can I make my
website’s structure more navigable?’, Software Usability Research
Laboratory; Department of Psychology; Wichita State University,
Wichita. Retrieved 14:26 UTC+1 26 April 2006 from
http://psychology.wichita.edu/optimalweb/structure.htm.
Bernard, M., Liao, C. & Mills, M. (2001), ‘Determining the Best Online
Font for Older Adults’, Software Usability Research Laboratory;
Department of Psychology; Wichita State University, Wichita.
Retrieved 18:46 UTC+1 26 April 2006 from http:
//psychology.wichita.edu/surl/usabilitynews/3W/fontSR.htm.
Bieri, R., Florack, A. & Scarabis, M. (2006), ‘Der Zuschnitt von Werbung
auf die Zielgruppe älterer Menschen’, Zeitschrift für
Medienpsychologie 18(1), 19–30.
Birren, J. E. & Schaie, K. W., eds (1990), Handbook of the Psychology of
Aging, Vol. 2 of The Handbooks of Aging, 3 edn, Academic Press,
San Diego.
Birren, J. E. & Schaie, K. W., eds (2006), Handbook of the Psychology of
Aging, Vol. 2 of The Handbooks of Aging, 6 edn, Elsevier Academic
Press, San Diego.
Bischoff, S. (2001), „Ältere Menschen – Why offline?“, in Gehrke (2001b),
pp. 13–23.
Bollwage, M. (2005), Typografie kompakt: Der richtige Umgang mit
Schrift am Computer, 2nd edn, Springer, Berlin, Heidelberg, New
York.
Brünner, B. O. (1997), Die Zielgruppe Senioren: eine interdisziplinäre
Analyse der älteren Konsumenten, Lang, Frankfurt am Main. Also:
PhD thesis, Helmut-Schmidt-Universität (Bundeswehr), Hamburg.
Cerella, J. (1990), Aging and Information-Processing rate, in Birren &
Schaie (1990), pp. 201–221.
90
Bibliography
Chadwick-Dias, A., McNulty, M. & Tullis, T. (2003), Web usability and
age: how design changes can improve performance, in ‘ACM
Conference on Universal Usability: Proceedings of the 2003
conference on Universal Usability in Vancouver, BC, Canada’, ACM
press, New York, pp. 30–37.
Craik, F. I. M. & Salthouse, T. A., eds (2000), The Handbook of Aging
and Cognition, 2nd edn, Lawrence Erlbaum Associates, Mahwah NJ,
London.
D’Aloisio, A. & Klein, R. M. (1990), Aging and the Development in
Visual Attention, in Enns (1990), pp. 447–466.
de Jager, P. (2005), ‘The Danger of the “Early Adopter” Myth’,
Retrieved 13:56 UTC+1, 14 April 2006 from
http://www.technobility.com/docs/article032.htm.
Demunter, C. (2005a), The digital divide in Europe, number 38/2005 in
‘Statistics in Focus’, Statistical Office of the European Communities
(Eurostat), Luxembourg. Available on-line from
http://epp.eurostat.cec.eu.int/cache/ITY_OFFPUB/KS-NP-05-038/
EN/KS-NP-05-038-EN.PDF.
Demunter, C. (2005b), Internet activities in the European Union, number
40/2005 in ‘Statistics in Focus’, Statistical Office of the European
Communities (Eurostat), Luxembourg. Available on-line from
http://epp.eurostat.cec.eu.int/cache/ITY_OFFPUB/KS-NP-05-040/
EN/KS-NP-05-040-EN.PDF.
destatis (2003), Im Jahr 2050 wird jeder Dritte in Deutschland 60 Jahre
oder älter sein, Statistisches Bundesamt (destatis), Wiesbaden.
Press release, 6 June 2003. Available on-line from
http://www.destatis.de/presse/deutsch/pm2003/p2300022.htm.
destatis (2006), Informationstechnologie in Unternehmen und Haushalten
2005: Tabellenanhang zur Pressebroschüre, Statistisches Bundesamt
91
Bibliography
(destatis), Wiesbaden. Appendage to Greiner et al. (2006). Available
on-line from http://www.destatis.de/download/d/veroe/
Tabellenanhang_Haushalte_IKT2005.pdf.
Dickinson, A., Newell, A. F., Smith, M. J. et al. (2005), ‘Introducing the
Internet to the over-60s: Developing an email system for older novice
computer users’, Interacting with Computers 17, 621–642.
Ellis, D. R. & Kurniawan, S. H. (2000), ‘Increasing the Usability of
Online Information for Older Users: A Case Study in Participatory
Design’, International Journal of Human–Computer Interaction
12(2), 263–276.
Emery, V. K., Edwards, P. J., Jacko, J. A. et al. (2002), Toward achieving
universal usability for older adults through multimodal feedback, in
‘ACM Conference on Universal Usability: Proceedings of the 2003
Enns, J. T., ed. (1990), The Development of Attention: Research and
Theory, North-Holland, Amsterdam, New York, Oxford.
Eurostat (2006), ‘Eurostat - data navigation tree’, Statistical Office of the
European Communities (Eurostat), Luxembourg. Retrieved 21:11
UTC+1, 14 April 2006 from
http://epp.eurostat.cec.eu.int/portal/page?_pageid=1996,
45323734&_dad=portal&_schema=PORTAL&screen=welcomeref&open=
/infosoc/policy&language=en&product=EU_MASTER_information_
society&root=EU_MASTER_information_society&scrollto=0.
Fox, S. (2001), ‘Wired seniors: A fervent few, inspired by family ties’,
PEW Internet & American Life Project, Washington, DC. Retrieved
14:21 UTC+1, 13 December 2005 from
http://www.pewinternet.org/pdfs/PIP_Wired_Seniors_Report.pdf.
Fox, S. (2004), ‘Older Americans and the Internet: Just 22 % go online,
but their enthusiasm for email and search may inspire their peers to
92
Bibliography
take the leap’, PEW Internet & American Life Project, Washington,
DC. Retrieved 15:26 UTC+1, 15 January 2005 from
http://www.pewinternet.org/pdfs/PIP_Seniors_Online_2004.pdf.
Fox, S. (2005), ‘Digital Divisions’, PEW Internet & American Life
Project, Washington, DC. Retrieved 20:33 UTC+1, 16 May 2006
from http://www.pewinternet.org/pdfs/PIP_Digital_Divisions_
Oct_5_2005.pdf.
Fox, S. & Madden, M. (2005), ‘Generations online’, PEW Internet &
American Life Project, Washington, DC. Retrieved 20:17 UTC+1,
16 May 2006 from
http://www.pewinternet.org/pdfs/PIP_Generations_Memo.pdf.
Fozard, J. L. (1990), Vision and Hearing in Aging, in Birren & Schaie
(1990), pp. 150–170.
Gappa, H. & Nordbrock, G. (2004), ‘Applying Web accessibility to
Internet portals’, Universal Access in the Information Society
3, 80–87.
Gauthier, A. H. & Smeeding, T. M. (2000), ‘Time use at older ages:
Cross-national Differences’, Organisation for Economic Co-operation
and Development (OECD), Paris. Retrieved 18:53 UTC+1, 19 May
2006 from http://www.oecd.org/dataoecd/20/24/2431647.pdf.
Gehrke, B. (2001a), Offline im Onlinezeitalter, in Ältere Menschen Neue
Medien – Why offline? (Gehrke 2001b), pp. 23–65.
Gehrke, B., ed. (2001b), Ältere Menschen Neue Medien – Why offline?,
Europäisches Zentrum für Medienkompetenz GmbH, Marl.
Goldstein, E. B. & Ritter, M. (1997), Wahrnehmungspsychologie,
Spektrum Akademischer Verlag, Heidelberg.
Gourmelon, A. (1994), Richtlinien für die gedächtnisfreundliche und
altersgerechte Gestaltung von Dialogschnittstellen, PhD thesis,
Friedrich-Alexander-Universität, Erlangen-Nürnberg.
93
Bibliography
Greiner, U., Hauschild, W., Kahle, I. et al. (2006),
Informationstechnologie in Unternehmen und Haushalten 2005,
Statistisches Bundesamt (destatis), Wiesbaden. Available on-line
from http://www.destatis.de/download/d/veroe/
Pressebroschuere_IKT2005.pdf.
Griffiths, P. (2004), ‘Elastic Design’, A List Apart. Retrieved 17:05
UTC+1, 26 April 2006 from
http://www.alistapart.com/articles/elastic/.
Gustafson, A. (2004), ‘Let Them Eat Cake’, A List Apart. Retrieved
13:55 UTC+1, 25 April 2006 from
http://www.alistapart.com/articles/eatcake/.
Hartley, A. (2006), Changing Role of the Speed of Processing Construct
in the Cognitive Psychology of Human Aging, in Birren & Schaie
(2006), pp. 183–207.
Hawthorne, D. (2003), How universal is good design for older users?, in
‘ACM Conference on Universal Usability: Proceedings of the 2003
Holt, B. (2000), Creating Senior-Friendly Web Sites, number 4/2000 in
‘Issue Brief’, Center for Medicare Education, Washington, DC.
Available on-line from
http://www.medicareed.org/PublicationFiles/V1N4.pdf.
Hoyer, W. J. & Touron, D. R. (2003), Learning in Adulthood, in
J. Demick & C. Andreoletti, eds, ‘Handbook of Adult Development’,
The Plenum Series in Adult Development and Aging, Kluwer
Academic/Plenum Publishers, New York, Boston, Dordrecht,
pp. 23–41.
Hoyer, W. J. & Verhaegen, P. (2006), Memory Aging, in Birren & Schaie
(2006), pp. 209–232.
94
Bibliography
Isserstedt, W., Middendorff, E., Weber, S. et al. (2004), Die
wirtschaftliche und soziale Lage der Studierenden in der
Bundesrepublik Deutschland 2003, 17. Sozialerhebung des Deutschen
Studentenwerks, Bundesministerium für Bildung und Forschung
(BMBF), Bonn, Berlin. Available on-line from
http://www.bmbf.de/pub/040714_soz17hauptbericht.pdf.
Kausler, D. H. (1991), Experimental Psychology, Cognition, and Human
Aging, 2nd edn, Springer, New York.
König, P. (2006), ‘IFeel mouse [Incident: 060320-001233]’, e-mail
correspondence with Logitech EMEA support, 20 March 2006; see
Appendix A. for transcript.
Krauss Whitbourne, S. (1996), Psychological Perspectives in the Normal
Aging Process, in L. L. Carstensen, B. A. Edelstein & L. Dornbrand,
eds, ‘The Practical Handbook of Clinical Gerontology’, Sage
Publications, Thousand Oaks Calif, pp. 3–35.
Krug, S. (2006), Don’t Make Me Think! A Common Sense Approach To
Web Usability, New Riders Publishing, Berkeley.
Kurniawan, S. & Zaphiris, P. (2005), Research-Derived Web Design
Guidelines for Older People, in ‘Assets ’05: Proceedings of the 7th
international ACM SIGACCESS conference on Computers and
accessibility’, ACM Press, New York, pp. 129–135.
Larson, K. & Czerwinski, M. (1998), Web Page Design: Implications of
Memory, Structure and Scent for Information Retrieval, in
‘Proceedings of CHI’98, Human Factor in Computing Systems (Los
Angeles, 21–23 April 1998)’, ACM press, New York, pp. 25–32.
Lehr, U. M. (2003), Psychologie des Alterns, 10th edn, Quelle & Meyer
Verlag, Wiebelsheim.
95
Bibliography
Lynch, P. & Horton, S. (2004a), ‘GRAPHICS: “Browser-safe” colors’,
Web Style Guide. Retrieved 19:41 UTC+1 22 April 2006 from
http://www.webstyleguide.com/graphics/safe.html.
Lynch, P. & Horton, S. (2004b), ‘TYPOGRAPHY: Typefaces’, Web Style
Guide. Retrieved 17:45 UTC+1 26 April 2006 from
http://www.webstyleguide.com/type/face.html.
Marsiske, M. & Margrett, J. A. (2006), Everyday Problem Solving and
Decision Making, in Birren & Schaie (2006), pp. 315–342.
Matthews, G., Davies, D. R., Westerman, S. J. et al. (2000), Human
performance: cognition, stress, and individual differences, Psychology
Press, Hove.
McDowd, J. M. & Birren, J. E. (1990), Aging and Attentional Processes,
in Birren & Schaie (1990), pp. 222–233.
McDowd, J. M. & Shaw, R. J. (2000), Attention and Aging: A Functional
Perspective, in Craik & Salthouse (2000), pp. 221–292.
Merriam-Webster Inc. (2006), ‘Merriam-Webster Online’,
Merriam-Webster Inc., Springfield, MA. Retrieved 09:22 UTC+1,
5 May 2006 from http://www.merriam-webster.com/.
Miller, C. S. & Remington, R. W. (2004), ‘Modeling Information
Navigation: Implications for Information Architecture’,
Human–Computer Interaction 19, 225–271.
Mollenkopf, H. (1998), Soziale Integration und Teilhabe alter Menschen
durch Technik, in T. Erkert & J. Salomon, eds, ‘Seniorinnen und
Senioren in der Wissensgesellschaft’, Kleine, Bielefeld, pp. 125–134.
Nayak, L., Priest, L. & Stuart-Hamilton, I. (2006), ‘Website design
attributes for retrieving health information by older adults: an
application of architectural criteria’, Universal Access in the
Information Society. Springer “Online First” article. DOI
96
Bibliography
10.1007/s10209-006-0029-9,
http://dx.doi.org/10.1007/s10209-006-0029-9.
NIA & NLM (2002), Making Your Website Senior Friendly: A Checklist,
National Institute of Aging (NIA) and National Library of Medicine
(NLM), Bethesda, MD. Available on-line from
http://www.nlm.nih.gov/pubs/checklist.pdf.
NIA & NLM (2006), ‘NIHSeniorHealth Health Information for Older
Adults’, National Institute of Aging (NIA) and National Library of
Medicine (NLM), Bethesda, MD. Retrieved 17:20 UTC+1,
17 January 2006 from http://nihseniorhealth.gov/.
Nielsen, J. (1993), Usability Engineering, Morgan Kaufmann, San Diego,
San Francisco, New York.
Nielsen, J. (1996), ‘Original Top Ten Mistakes in Web Design’, Jakob
Nielsen’s AlertBox. Retrieved 17:39 UTC+1, 5 May2006 from
http://www.useit.com/alertbox/9605a.html.
Nielsen, J. (1997), ‘Changes in Web Usability Since 1994’, Jakob
Nielsen’s AlertBox. Retrieved 17:47 UTC+1, 5 May2006 from
http://www.useit.com/alertbox/9712a.html.
Nielsen, J. (2000), Designing Web Usability: The Practice of Simplicity,
New Riders Publishing, Indianapolis.
NINDS (2006), ‘NINDS Parkinson’s Disease Information Page’, National
Institute of Neurological Disorders and Stroke (NINDS), Bethesda,
MD. Retrieved 12:54 UTC+1, 15 May 2006 from http://www.ninds.
nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm.
Philipp, D. & Kliegl, R. (2000), Gedächtnistraining, in H.-W. Wahl &
C. Tesch-Römer, eds, ‘Angewandte Gerontologie in
Schlüsselbegriffen’, Verlag W. Kohlhammer, Stuttgart, Berlin, Köln,
pp. 97–101.
97
Bibliography
Plattig, K.-H. (1984), Sinnesorgane, in W. D. Oswald, W. M. Hermann,
S. Kanowski et al., eds, ‘Gerontologie - Medizinische, psychologische
und sozialwissenschaftliche Grundbegriffe’, Kohlhammer, Stuttgart,
pp. 421–429.
Plude, D. J. (1990), Aging, Feature Integration, and Visual Selective
Attention, in Enns (1990), pp. 467–487.
Rogers, E. M. (2003), Diffusion of Innovations, 5th edn, Free Press, New
York, London, Toronto.
Rosenfeld, L. & Morville, P. (2002), Information Architecture for the
World Wide Web, 2nd edn, O’Reilly.
Schaie, K. W. (2005), Developmental Influences on Adult Intelligence:
The Seattle Longitudinal Study, Oxford University Press, Oxford,
New York.
Schaie, K. W. & Willis, S. L. (1991), Adult Development and Aging,
HarperCollins Publishers, New York.
Schieber, F. (2006), Vision and Aging, in Birren & Schaie (2006),
pp. 129–161.
Schneider, B. A. & Pichora-Fuller, M. K. (2000), Implications of
Perceptual Deterioration for Cognitive Aging Research, in Craik &
Salthouse (2000), pp. 155–219.
Schneider, K., Götzl, H. & Henrich, S. (1994), Motivation und Gedächtnis
im Alter, in W. Kuhn, T. Büttner, W. Heinemann et al., eds,
‘Altern, Gehirn und Persönlichkeit’, Verlag Hans Huber, Bern,
Göttingen, Toronto, pp. 109–118.
Shneiderman, B. & Plaisant, C. (2005), Designing the User Interface:
Strategies for Effective Human–Computer Interaction, 4th edn,
Pearson Education/Addison Wesley, Boston, San Francisco, New
York.
98
Bibliography
Singh, N. & Pereira, A. (2005), The Culturally Customized Web Site:
Customizing Web Sites for the Global Marketplace, Elsevier
Butterworth–Heinemann, Burlington, Oxford.
Spirduso, W. W. (1995), Physical Dimensions of Aging, Human Kinetics,
Champaign, Windsor, Leeds.
Spool, J. M., Scanlon, T., Schroeder, W. et al. (1999), Web Site Usability:
A Designer’s Guide, Morgan Kaufmann, San Francisco, San Diego,
New York.
Stadelhofer, C. (2000), ‘Möglichkeiten und Chancen der Internetnutzung
durch ältere’, Zeitschrift für Gerontologie und Geriatrie
33(3), 186–194.
Stadtverwaltung Aachen (1994), ‘Dienstvereinbarung über den Einsatz
technikunterstützter Informationsverarbeitung bei der
Stadtverwaltung Aachen’, Stadtverwaltung Aachen. Retrieved
31 May 2006 from http://www.aachen.de/de/stadt_buerger/pdfs_
stadtbuerger/pdf_personalrat/vereinbarungen/tuiv.pdf.
Venkatesh, V., Morris, M. G., Davis, G. B. et al. (2003), ‘User acceptance
of information technology: Toward a unified view’, MIS Quarterly
27(3), 425–478.
Verrillo, R. T. & Verrillo, V. (1985), Sensory and Perceptual
Performance, in N. Charness, ed., ‘Aging and Human Performance’,
John Wiley & Sons, Chichester, New York, Brisbane, pp. 1–46.
Wikipedia, the free encyclopedia (2006a), ‘Color blindness’, Wikipedia –
The Free Encyclopedia. Retrieved 15:08 UTC+1. 27 June 2006 from
http://en.wikipedia.org/w/index.php?title=Color_
blindness&oldid=60766235.
Wikipedia, the free encyclopedia (2006b), ‘Digital divide’, Wikipedia –
The Free Encyclopedia. Retrieved 20:13 UTC+1. 16 May 2006 from
99
Bibliography
http://en.wikipedia.org/w/index.php?title=Digital_
divide&oldid=53166723.
Wirth, T. (2004), Missing Links: Über gutes Webdesign, 2nd edn, Hanser
Fachbuchverlag, München.
Zacks, R. T., Hasher, L. & Li, K. Z. H. (2000), Human Memory, in Craik
& Salthouse (2000), pp. 293–357.
Zarit, J. M. & Zarit, S. H. (1987), Molar Aging: The Physiology and
Psychology of Normal Aging, in L. L. Carstensen & B. A. Edelstein,
eds, ‘Handbook of clinical gerontology’, Vol. 146 of Pergamon
general psychology series, Pergamon Press, New York, pp. 18–31.
100

1 Introduction and Preliminary Considerations

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