PowerPoint Presentation
Classification
Learning by Recording Cases
Incremental Concept Learning
Version Spaces
Classification
Learning
Lesson Preview
Learning concepts
Equivalence classes
Concept hierarchies
Types of concepts
Bottom-up search
Which of these are birds?
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Image credits:
Carl Chapman, http://www.flickr.com/photos/12138336@N02/1997128094/
Elaine Wilson, http://www.naturespicsonline.com/Nature15/
Nicor, https://commons.wikimedia.org/wiki/User:Nicor
Samuel Blanc, http://www.sblanc.com/
Urville Djasim, https://secure.flickr.com/photos/urville_djasim/3611889680/
Daniel Vianna, https://commons.wikimedia.org/wiki/User:Mr.Rocks
Alessandro Di Grazia, http://www.petsugargliders.eu/
Jaroslav Novák, https://commons.wikimedia.org/wiki/File:Duck_Hen.jpg
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…
Has wings?
Has feathers?
Has talons?
Has a beak?
Flies?
Runs?
Lays eggs?
Carnivorous?
Vegetarian?
Blue?
Red?
Swims?
Builds nests?
…
Cognitive System
Reaction
Deliberation
Metacognition
Reasoning
Learning
Memory
Input
Output
Input
Output
Cognitive System
…
Has wings?
Has feathers?
Has talons?
Has a beak?
Flies?
Runs?
Lays eggs?
Carnivorous?
Vegetarian?
…
→
2m actions
Input
Output
Cognitive System
2n percepts
→
2m actions
Input
Output
Cognitive System
10 percepts= 1024 combinations
100 percepts = 1.2 × 1030 combinations
= 1.2 nonillion combinations
300 percepts = 2.0 × 1090 combinations
= more combinations thanatoms in the universe
Input
Output
Cognitive System
2n percepts
→
2m actions
Input
Output
Cognitive System
2n percepts
→ k concepts →
2m actions
Input
Output
Cognitive System
2n percepts
→ k concepts →
2m actions
“Equivalence Classes”
EagleBluebirdPenguin
Lays eggs?
ο Yesο Noο Maybe
Has wings?
ο Yesο Noο Maybe
Has talons?
ο Yesο Noο Maybe
Flies?
ο Yesο Noο Maybe
Has fur?
ο Yesο Noο Maybe
Large?
ο Yesο Noο MaybeLays eggs?
ο Yesο Noο Maybe
Has wings?
ο Yesο Noο Maybe
Has talons?
ο Yesο Noο Maybe
Flies?
ο Yesο Noο Maybe
Has fur?
ο Yesο Noο Maybe
Large?
ο Yesο Noο MaybeLays eggs?
ο Yesο Noο Maybe
Has wings?
ο Yesο Noο Maybe
Has talons?
ο Yesο Noο Maybe
Flies?
ο Yesο Noο Maybe
Has fur?
ο Yesο Noο Maybe
Large?
ο Yesο Noο Maybe
For each of these three animals, choose the value for each percept that applies to that animal.
Block
Brick
Wedge
is-a
is-a
Vertebrate
Bird
Reptile
Mammal
Bluebird
Penguin
Eagle
Bird
Lays eggs?
ο Yesο Noο Maybe
Has wings?
ο Yesο Noο MaybeHas talons?
ο Yesο Noο Maybe
Flies?
ο Yesο Noο MaybeHas fur?
ο Yesο Noο Maybe
Large?
ο Yesο Noο Maybe
How would you characterize the class ‘bird’ given the characterization of its subclasses below?
EagleBluebirdPenguin
Lays eggs?Yes
Has wings?Yes
Has talons? Yes
Flies?Yes
Has fur? No
Large?YesLays eggs?Yes
Has wings?Yes
Has talons? Yes
Flies?Yes
Has fur? No
Large? NoLays eggs?Yes
Has wings?Yes
Has talons?No
Flies? No
Has fur? No
Large?Yes
More formal
Less formal
Axiomatic concepts
Prototype concepts
Exemplar concepts
Axiomatic concepts:
Concepts defined by a formal set of necessary and sufficient conditions.
Example: a circle
Axiomatic concepts:
Concepts defined by a formal set of necessary and sufficient conditions.
Circle: all points in a plane that are equidistant from a single point.
Prototype concepts:
Base concepts defined by a typical example with overridable properties.
Example: a chair
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Prototype concepts:
Base concepts defined by a typical example with overridable properties.
Chair
#-of-legs : fourmaterial : metal
has-back : true
has-arms : false
is-cushioned : false
…
Prototype concepts:
Base concepts defined by a typical example with overridable properties.
Chair
#-of-legs : four
material : metal
has-back : true
has-arms : false
is-cushioned : false
…
Stool
has-back : false
…
Folding chair
has-back : true
#-of-legs : four
has-arms : false
…
Exemplar concepts:
Concepts defined by implicit abstractions of instances, or exemplars, of the concept.
Example: beauty
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Exemplar concepts:
Concepts defined by implicit abstractions of instances, or exemplars, of the concept.
Image credit:
DNGDesign, http://dngdesign.deviantart.com/art/Sunset-361106086
scillystuff, http://www.flickr.com/people/55296256@N00
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More formal
Less formal
Axiomatic concepts
Prototype concepts
Exemplar concepts
More formal
Less formal
Rank the following concepts based on their formality:
Inspirational
Reptile
Foo
Right Triangle
Holiday
Saltiness
4. Right Triangle
2. Reptile
3. Foo
5. Holiday
1. Inspirational
6. Saltiness
Vertebrate
Bird
Reptile
Mammal
Bluebird
Penguin
Eagle
GDP
Future of
Dow Jones
Industrial
Average
Inflation
Employment
Overtime
Hours
New
Orders
Index
Consumer
Sentiment
Index
Jobless
Claims
Commodity
Futures
Index
NASM
ISM
PMI
GDP
3/4ths
Age
Job
Vacancies
Actual
Hours
Worked
Assignment
How would you use classification to design an agent that could answer Raven’s progressive matrices?
To recap…
Concept learning
Equivalence classes
Concept hierarchies
Axiomatic, prototypical, and exemplar concepts
Bottom-up search
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