lect 0514 p

Transcription

lect 0514 p
IST 4 Information and Logic
Associative Memories
A Case Study with Remote Association Test
Yue Li
Call Phone Fence
Car Valve
Caltech MIT
Pen Blue Cheese
BabylonTablet
Suzanne Corkin
Henry Molaison or H. M.
(1926 2008)
(1926-2008)
Part of H. M.’s brain is removed for treating epilepsy in 1953.
After the surgery
surgery, he suffered from severe amnesia.
amnesia
Scientists worked with H.M. for more than 40 years.
William Scoville
(1906 – 1984)
Brenda Milner
(1918 - )
Metal – Iron
Baby – Cries
Crush – Dark
School – Grocery
Rose – Flower
Obey – Inch
Fruit – Apple
Cabbage – Pen
“Do
Do you remember what
went with Metal? Baby?
Crush?...”
First trial: Iron
Second trial: Cries, Iron, Flower
Third trial: Apple, Cries, Iron
Henry Molaison or H. M.
(1926-2008)
The Storyy of S.
“Nel mezzo del cammin di nostra vita …”
Alexander Luria
(1902 – 1977)
“
(Nel) – I was paying my membership dues when
there, in the corridor, I caught sight of the ballerina
Nel’skaya
Nel
skaya.
(Mezzo) – I myself am a violinist; what I do is to set
up an image of a man, together with Nel’skaya, who
is playing the violin.
(Del) – There’s a pack of Deli Cigarettes near them.
(Cammin) – I set up an image of a fireplace close
by.
(Di) – Then I see a hand pointing toward a door.
”
Memory champions have average
memories.
They memorize in a different way
using navigation, association and
visualization.
Joshua Foer
Good memories can be trained.
Association and Creative Thinking
Creative thinkingg connects different ideas together
g
and generates a new idea.
Prof. Mednick proposed remote association tests
Prof
in 1960s for evaluating a person’s creativity.
S
Sarnoff
ff A
A. Mednick
M d i k
Sk
Skate
C
Cream
Ice
Water
Falling
Dust
Star
Actor
Boot
Summer
Camp
Ground
Fence
Card
Post
Master
Remote Association Test
Cue #1
Cue #2
Fence
Card
Solution
P
Post
Cue #3
Master
We want to synthesize the
process for solving RATs.
RATs
Why ?
Wouldn’t it be nice if …
Caltech
Astronomy
JJet Propulsion
p
Laboratoryy
Pasadena
Why do we want to solve RAT
• Captures word associations
– Building blocks for associating large datasets, e.g.,
webpages,
b
databases,
d b
documents.
d
• Potentials for interesting applications
– Artificial brainstorming.
g
– Brain-like memory organization.
– Artificial experts.
experts
Solvingg RATs
Human: Knowledge + Strategy/Tricks
Machine: Database/Data structures + Algorithms
Captures word
associations
Search in data
structures
A Good Database
• Human Brain Cloud
– http://www.humanbraincloud.com
– A social game by Kyle Gabler.
– Word associations contributed by
crowd sourcing.
Why HBC Database ?
http://www.humanbraincloud.com/#stats
• Using humans
• Completeness
– Many words
– Many connections
Word Association Graph
p
Caltech
0.1
0.7
0.6
Astronomy
0.5
0.3
0.2
0.3
Telescope
0.2
JPL
0.3
Uni ersit
University
0.1
0.1
Sunny
Pasadena
0.6
HBC Graph
G h Demo
D
Demo #1
D(x, y): the shortest distance from x to y
D(Caltech, Telescope) = 2
Caltech
01
0.1
07
0.7
0.6
Astronomy
0.5
Tl
Telescope
Asymmetric
0.2
0.3
0.2
0.3
JPL
0.3
U
University
0.1
0.1
Sunny
Pasadena
0.6
Symmetric Distance: SD(x, y) = min{ D(x, y), D(y, x) }
SD(C l h JPL) = min
SD(Caltech,
i { 22, 1 } = 1
Caltech
01
0.1
07
0.7
0.5
Tl
Telescope
0.6
Astronomy
0.2
0.3
0.2
0.3
JPL
0.3
U
University
0.1
0.1
Sunny
Pasadena
0.6
Sphere(w, r): all the words within distance r
SSphere(Pasadena,
h (P d
1) = {JPL,
{JPL Caltech,
C lt h Sunny}
S
}
Sphere(Pasadena, 2) = {JPL, Caltech, Sunny, Telescope, Astronomy, University}
Caltech
01
0.1
07
0.7
0.5
Tl
Telescope
0.6
Astronomy
0.2
0.3
0.2
0.3
JJPL
0.3
University
0.1
0.1
Sunny
Pasadena
0.6
Sphere Intersection
S h (A
Sphere(Astronomy,
1) ∩ Sphere(JPL,
S h (JPL 1) = { Telescope
Tl
}
Caltech
01
0.1
07
0.7
0.5
Tl
Telescope
0.6
Astronomy
0.2
0.3
0.2
0.3
JJPL
0.3
University
0.1
0.1
Sunny
Pasadena
0.6
An Algorithm of the RAT Solver
• Compute the radius-3 sphere intersection of the cue words*
• Prune the sphere intersection
– take the words with minimum sum of symmetric distances
from the cue words.
words
• Shorten the candidate set with predefined metric to
yield top-K solutions
– e.g. using the multiplication of the edge probabilities
*our demo to be shown later uses radius-2 ball intersection for faster execution speed.
A Toyy Example
p
Caltech
Astronomy
?
Pasadena
Compute
p
Sphere
p
Intersection
Caltech
0.1
0.7
0.5
Telescope
0.6
Astronomy
0.2
0.3
0.2
0.3
JPL
0.3
Uni ersit
University
0.1
0.1
Sunny
Pasadena
0.6
Prune Sphere Intersection
SD(Telescope, Astronomy)
SD(S
SD(Sunny,
A
Astronomy)
)
SD(JPL, Astronomy)
SD(University, Astronomy)
+ SD(Telescope, Caltech)
+ SD(Sunny,
SD(S
C l h)
Caltech)
+ SD(JPL, Caltech)
+ SD(University, Caltech)
+
+
+
+
SD(Telescope, Pasadena) = 5
SD(S
SD(Sunny,
P d )
Pasadena)
=6
SD(JPL, Pasadena)
=3
SD(University, Pasadena) = 6
Caltech
0.1
0.6
Astronomy
0.7
0.5
Telescope
0.2
0.3
0.2
03
0.3
JPL
0.3
University
0.1
0.1
Sunny
Pasadena
0.6
Walk-through Examples with
Real RATs
Demo #2
Performance (k = 1)
In 84.9% RATs, the real solutions appear in the pruned intersection.
In 70.8% RATs, the final solution is correct.
* All RATs are collected from
www.remote-associates-test.com
Difficulty characterized by the
average solving time of human beings.
Performance (k = 3, 4, 6, 8)
In 80% RATs, the real solutions appear in the top-k solution list.
Success Rate
Average Precision (k =1, 3, 4, 6, 8)
increases slowly with k when k > 3
A better association
graph is needed
Ongoing Work for Solving RATs
• Better
B
algorithms
l
h
– Improving distance metric
– Lowering complexity
• Better databases
– Generatingg association graphs
g p with better quality
q
y
• Utilizing the semantics of and the relationships between
words
Flower
Fight
Rose
Up
Future Directions
• How to generate association graphs?
– How to determine the quality of a graph?
– Domain specific graph
• Medicine, NSA, marketing, patents, papers, people
• How to access the quality of a domain specific graph?
• How to determine the difficulty level of a RAT?
• Can we create RAT using an association graph?
Ideas and Questions
If you have
ave any
a y quest
questions,
o s, new
ew ideas,
eas, or
o want
wa t
to work with us, please drop us an email!
y @ca tec .e u
yli@caltech.edu