Why Visualization? - Information Engineering Group
Transcription
Why Visualization? - Information Engineering Group
Information Visualization & Visual Analytics Wolfgang Aigner, Technische Universität Wien, aigner@ifs.tuwien.ac.at 13. Juni 2012 Outline About me Motivation & Introduction Visualization Design The Good - The Bad – The Ugly Examples Visual Analytics Demo Resources 2 About me 3 MOTIVATION & INTRODUCTION Information overload [Howson, 2008] 7 Why Visualization? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 599 525 541 542 527 505 469 409 321 318 321 243 250 253 246 230 196 192 134 94 25 87 128 183 163 693 693 662 611 579 529 553 558 531 606 693 693 660 579 527 489 510 497 508 493 423 467 482 473 568 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 541 542 527 505 469 409 321 318 321 243 250 253 246 230 196 192 134 94 541 542 527 505 469 409 321 558 531 606 693 693 660 579 527 489 510 497 508 493 423 467 482 473 568 558 531 606 693 693 660 579 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 318 321 243 250 253 246 230 196 192 134 94 541 542 527 505 469 409 321 318 321 243 250 253 246 230 527 489 510 497 508 493 423 467 482 473 568 558 531 606 693 693 660 579 527 489 510 497 508 493 423 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 196 192 134 94 318 321 243 250 253 246 230 196 318 321 243 250 253 246 230 196 318 321 243 250 253 467 482 473 568 558 531 606 693 693 660 579 527 489 510 497 508 493 423 467 482 473 568 482 473 568 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 246 230 196 230 196 318 321 243 250 253 246 230 230 196 318 321 243 250 253 246 606 693 693 660 579 527 489 606 693 693 660 579 527 489 510 497 508 493 423 467 8 Goal 9 Method 10 Human Vision high bandwidth fast, parallel pattern recognition pre-attentive increases cognitive resources expand human working memory “The eye... the window of the soul, is the principal means by which the central sense can most completely and abundantly appreciate the infinite works of nature.” Leonardo da Vinci (1452 – 1519) [Few, 2006] 11 Example 12 Example 13 INTERACTIVITY Car Example - Interactivity 16 VISUALIZATION DESIGN Three central questions data representations & interaction goal/task appropriateness user/audience Who are the users of the systems? (Users) What kind of data are they working with? (Data) What are the general tasks of the users? (Tasks) 18 Purpose Exploration / Explorative Analysis undirected search no a priori hypotheses get insight into the data begin extracting relevant information come up with hypotheses interactivity Confirmation / Confirmative Analysis directed search verify or reject hypotheses Presentation communicate and disseminate analysis results 19 InfoVis Reference Model [Card et al., 1999] 20 Visual Variables – Mackinlay [Mackinlay, 1987] 21 Visual Mapping: Example year length popularity subject award? [garysaid.com] 22 Visual Mapping: Example [Spotfire] 23 THE GOOD Florence Nightingale – Rose chart (1855) [Nightingale, 1858] 25 Guttenberg Plagiarism Gregor Aisch, Plagiatszeilen in der Guttenberg-Dissertation, Created at: March 1, 2011, Retrieved at: August 31, 2011, http://vis4.net/blog/de/posts/ guttenberg-plagiarism/ 26 Weather chart Aigner, Miksch, Tominski, Schumann. Visualization of Time-Oriented Data, Springer, 2011. 27 »Diagrams can lead to great insight, but also to the lack of it.« Tufte, 1997 THE BAD 29 The Challenger Disaster January 27, 1986: US-Space Shuttle Challenger explodes 72 seconds after launch Reasons: Sealing-rings in the right booster were damaged due to weather conditions Reliability-problems of the so-called O-rings were known 30 Challenger Disaster The manufacturer of the boosters warned NASA before launch that the expected cold temperatures might be an extra risk. NASA did not see any correlation between the failing of O-Rings and the temperatures. This was wrong! 31 Challenger Disaster: Tufte‘s Re-Visualization Edward R. Tufte showed that the risk would have been obvious to NASA engineers if a better visualization would have been used 32 Visualization Design data representations & interaction goal/task appropriateness user/audience Expressiveness A visualization is considered to be expressive if the relevant information of a dataset (and only this) is expressed by the visualization. The term "relevant" implies that expressiveness of a visualization can only be assessed regarding a particular user working with the visual representation to achieve certain goals. „A visualization is said to be expressive if and only if it encodes all the data relations intended and no other data relations.“ [Card, 2008, p. 523] [Mackinlay, 1986] Effectiveness A visualization is effective if it addresses the capabilities of the human visual system. Since perception, and hence the mental image of a visual representation, varies among users, effectiveness is user-dependent. Nonetheless, some general rules for effective visualization have been established in the visualization community. „Effectiveness criteria identify which of these graphical languages [that are expressive], in a given situation, is the most effective at exploiting the capabilities of the output medium and the human visual system.“ [Mackinlay, 1986] THE UGLY Tell the truth about the data [Tufte, 1983] Lie factor = Size of effect shown in graphic / Size of effect in data Fuel Economy Standard Redesign Lie Factor Lie Factor: 141 Beer Sales Redesign Christian Resei, AK-NÖ, treffpunkt 04/10, Magazin der NÖ Arbeiterkammer, S. 6 41 Example Tufte Design Principles 1. Above all else show the data. 2. Maximize the data-ink ratio. 3. Erase non-data-ink. 4. Erase redundant data-ink. 5. Revise and edit. [Tufte, 1983] VISUALIZATION TECHNIQUE EXAMPLES Newsmap / Treemap Marcos Weskamp, Newsmap, Retrieved at: Oct 14, 2011, http://newsmap.jp 45 Example: File Structure to Tree File System: 3 Folders Root Dir 1 File 1 6 Files 1) Root -> whole Screen Root File 2 Dir 2 File 3 Dir 3 1 MB 2 MB 2 MB File 4 3 MB File 5 1 MB File 6 1 MB Example: File Structure to Tree File System: 3 Folders 6 Files 2) Cutting - according to the size (30% and 70% of the space) Dir 1 Root Dir 2 Root Dir 1 File 1 1 MB File 2 2 MB Dir 2 File 3 2 MB Dir 2-1 File 4 3 MB File 5 1 MB File 6 1 MB Example: File Structure to Tree File System: Root Dir 1 File 1 3 Folders 6 Files File 2 2 MB Dir 2 File 3 2 MB Dir 2-1 3) Iteration: folder and subfolder File 1 File 2 File 1 Root Dir 2 1 MB File 3 Root File 2 Dir 2-1 File 4 3 MB File 5 1 MB File 6 1 MB Example: File Structure to Tree File System: Root Dir 1 File 1 3 Folders 6 Files File 2 2 MB Dir 2 File 3 2 MB Dir 2-1 File 3 Root File 2 File 4 File 6 File 1 File 5 One Solution 1 MB File 4 3 MB File 5 1 MB File 6 1 MB Horizon Graph [Reijner, 2005] visualization technique for comparing a large number of time-dependent variables based on the two-tone pseudo coloring Cycle Plot [Cleveland, 1994] technique to make seasonal and trend components visually discernable showing individual trends as line plots embedded within a plot that shows the seasonal pattern mean value for each weekday as grey line VISUAL ANALYTICS Analytical Methods Screen Resolution: 1024 * 768 = 786.432 Yearly Measurements of Water Level in Low.Austria:1 5.256.000 Number of Cellular Phones in Austria (2005):2 8.160.000 Transmitted Emails Every Hours (World-Wide):3 Whole Data often not Presentable 1. Applying Analytical Methods (Data Reduction) 2. Visualization of Most Important Data and Information 35.388.000 today: peta (1015) tomorrow: exa (1018) & zeta (1021) Analytical Methods Statistics, Machine Learning & Data Mining 1 ... Amt der NÖ Landesregierung, Abt. WA5 - Hydrologie, http://www.noel.gv.at/SERVICE/WA/WA5/htm/wnd.htm 2 ... CIA Factbook, https://www.cia.gov/cia/publications/factbook/ 3 ... How Much Information?, UC Berkeley, http://www2.sims.berkeley.edu/research/projects/how-much-info-2003/ Visual Analytics – What is it? James Thomas & Kristin A. Cook NVAC (National Visualization and Analytics Center), Seattle, USA “Visual Analytics is the science of analytical reasoning facilitated by interactive visual interfaces” DEMO TimeRider [Rind, et al., 2011-2012] BOOKS & RESOURCES Eduard Tufte 1983 / 2001 1990 1997 2006 61 Stephen Few Show Me the Numbers: Designing Tables and Graphs to Enlighten, Analytics Press, 2004 Information Dashboard Design: The Effective Visual Communication of Data, O'Reilly Media, 2006 Now You See It: Simple Visualization Techniques for Quantitative Analysis, Analytics Press, 2009 62 Web resources InfoVis:Wiki (http://www.infovis-wiki.net) Visual Analytics Digital Library (http://vadl.cc.gatech.edu/) … etc. … Infosthetics Blog (http://infosthetics.com/) EagerEyes.org (http://eagereyes.org/) … etc. … see http://www.infovis-wiki.net/index.php?title=Category:Web_resources for more 63 Commercial Software Tableau Spotfire MagnaView 64 Free tools and libraries No programming required Tableau Public - Free service that lets you create and share data visualizations on the web. http://www.tableausoftware.com/products/public Many Eyes - Free visualization site from IBM Research. http://manyeyes.alphaworks.ibm.com/manyeyes/ Google Chart Tools - Rich gallery of interactive charts and data tools http://code.google.com/apis/chart/ Gapminder World - Flash based Visualization that shows the world development indicators with a Scatterplot, Map and Animation (for Time). http://tools.google.com/gapminder/ Google Fusion Tables - Collaborative online visualization with community features similar to Manyeyes. http://tables.googlelabs.com/ Programming required Processing - Java-based open source programming language and environment http://processing.org/ Protovis - JavaScript library that composes custom views of data with simple marks such as bars and dots. http://www.protovis.org/ d3.js - Small, free JavaScript library for manipulating documents based on data. http://mbostock.github.com/d3/ prefuse - visualization framework for Java http://prefuse.org/ flare - ActionScript library for visualizations that run in the Adobe Flash Player. http://flare.prefuse.org/ JFreeChart - Java class library for generating charts. http://www.jfree.org/jfreechart/index.html 65 Summary: InfoVis... ... is a very complex task ... can help to get insight into data more quickly ... requires preparation and sensible handling of the information ... should make use of the properties of human visual perception ... requires sensible handling, relative to the task ... is a big challenge, if you want to do it good 66 See & Understand Detect the Expected - Discover the Unexpected Kontakt Dipl.-Ing. Dr. Wolfgang Aigner Technische Universität Wien Institut für Softwaretechnik & Interaktive Systeme Favoritenstr. 9-11/188 1040 Wien T +43 (1) 58801-18833 E aigner@ifs.tuwien.ac.at Thanks to www.cvast.tuwien.ac.at Thanks to Alessio Bertone Thomas Turic (Danube Universty Krems) (Danube Universty Krems) Heidrun Schumann Christian Tominski (University of Rostock) (University of Rostock) Silvia Miksch Bilal Alsallakh Paolo Federico Theresia Gschwandtner Klaus Hinum Katharina Kaiser Tim Lammarsch Alexander Rind Andreas Seyfang (CVAST, Vienna University of Technology) (CVAST, Vienna University of Technology) (CVAST, Vienna University of Technology) (CVAST, Vienna University of Technology) (in2vis, Vienna University of Technology) (CVAST, Vienna University of Technology) (HypoVis, Vienna University of Technology) (HypoVis, Vienna University of Technology) (Brigid, Vienna University of Technology) Margit Pohl Markus Rester (CVAST, Vienna University of Technology) (Vienna University of Technology) NEW BOOK Wolfgang Aigner • Silvia Miksch Heidrun Schumann • Christian Tominski Visualization of Time-Oriented Data with a foreword by Ben Shneiderman Springer 1st Edition, 2011, XVIII, 286 p. 221 illus., 198 in color. Hardcover, ISBN 978-0-85729-078-6. Table of Contents Introduction • Historical Background • Time & Time-Oriented Data • Visualization Aspects • Interaction Support • Analytical Support • Survey of Visualization Techniques • Conclusion www.timeviz.net survey.timeviz.net www.infovis-wiki.net Contribute & Benefit!