categories - presentation on rosch

8/13/2019 Categories - Presentation on Rosch

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Categorization


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J. L. Borges (1966) Other inquisitions 1937-1952. N. Y.,

Washington Square Press. Quoted in Ro sch, E. (1978) Principles of

categorization. In Rosch & Lloyd, Cognition and categorization.

The following is a taxonomy of the animal kingdomattributed to an ancient

chinese encyclopedia entitled the Celestial Emporium of Benevolent

Knowledge:

On those remote pages it is written that animals are dividedinto (a) those that belong to the Emperor, (b) embalmed

ones, (c) those that are trained, (d) suckling pigs, (e)

mermaids, (f) fabulous ones (g) stray dogs, (h) those that

are included in this classification, (i) those that tremble, (j)

innumerable ones, (k) those drawn with a very fine camels

hair brush, (l) others, (m) those that have just broken a

flower vase, (n) those that resemble flies from a distance.


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If these arent good categories, what are?

Ones used frequently in communication


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Good categories

Rosch

1. Cognitive Economy

Reduce number of discriminations in world

Cant have separate label for each thing Informativeness

Knowing that something is an X tells us more


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Good categories





These goals are at odds


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Good categories



Yields few large categories Informativeness

Yields many small categories


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Good categories





2. Reflect perceived structure of world

Correlated features feathers/beaks

Utility for us


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Vehicles

car truck boat

Furniture

chair lamp rug

Animals

snake dog cow

sedan station

wagon

garbage dump row motor

easy kitchen table floor Chinese rag

garter rattle Pekinese mutt milk beef


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Two dimensions of categorization

Vertical: Level of abstraction or

inclusiveness

Horizontal: Organization within categories


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Vertical

What are you si tt ing on?

What is this I am wearing?


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Vertical

What are you si tt ing on?

Chair, not auditorium chair or furniture

What is this I am wearing?

Sweater, not wool sweater or clothing

Preferred level of reference, why?


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List features common to members of the

following categories: Apple

Tools

Shirt Furniture

Green grapes

Watermelon

Shoes

Denim pants


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Preferred level of abstraction

Informativeness: Indexed by features

Highest-->middle: Large increase

Middle-->lowest: Small increase


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Preferred level of abstraction

Informativeness: Indexed by features

Highest-->middle: Large increase

Superordinate (vehicle) to basic level (car)

Middle-->lowest: Small increase

Basic level (car) to subordinate (4-door)


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Book review of pretentious novel:

And so, after putting away my 10 year old royal 470

manual and lining up my Mongol number 3

pencils on my Goldsmith Brothers Formica

imitation-wood desk, I slide into my oversize

squirrel-skin L. L. Bean slippers and shuffle off to

the kitchen. There, holding Decades in my

trembling right hand, I drop it, plunk, into my newSears 20-gallon, celadon-green Permanex trash

can.


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Why do these measures converge at

Basic Level?


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Basic Level distinguished by

convergence of many cognitive tasks: Common attributes

Similarity of shapes Appearance

Identifiabili ty of sha pes

Imagery

Motor programs Behavior

C om mu ni cat io n: l abe li ng

Communica tion : fa stes t ve ri fica tion

Development : f ir st l abels in l ex icon Dev elop me nt : ca te go ri za tion Communication

Language: earl ies t d if ferent ia tion with in language

Language: most f requent, shortes t labels

Language: bas ic l evel t erms neu tral


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Parts & Basic Level

Tversky & Hemenw ay

Among attributes, parts proliferate at basic

level

Parts form a bridge from appearance to

behavior


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Vertical Dimension of Categorization

Goals of categorization

Cognitive economy

Informative

Reduce # d iscr iminat ions

Reflect perceived structure of world

Basic level maximizes informativeness given #

categories that must be kept in mind

Many cognitive tasks converge on basic level

Parts underlie convergence


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What about categories of other things?

Scenes

People

Events


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Horizontal Dimension of Categorization

Characterize internal structure of categories

Knowledge representation of categories

Meaning of categories


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Early view of categorization

World is full of things varying on many

dimensions

Different cultures draw category boundaries indifferent places, color, corn, parrot, aunt

If categories are unit of thought, then different

cultures think differently


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Early view of categorization

World is full of things varying on many

dimensions

Different cultures draw category boundaries indifferent places, color, corn, parrot, aunt

If categories are unit of thought, then different

cultures think differently

BUT, cultures differ in environments, needs


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Sapir-Whorf Hypothesis:

Language shapes Thought

How do you separate culture from language?


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Conditions for testing Whorf Hypothesis

Languages differ with respect to an attribute

Physical, culture-free measure of attribute

Non-linguistic dependent measure

Prevalent attribute; culture independent


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Conditions for testing Whorf Hypothesis

Languages differ with respect to an attribute

Physical, culture-free measure of attribute

Non-linguistic dependent measure

Prevalent attribute; culture independent

Color


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Codability of color predicts memoryBrown & Lenneberg

Group 1: codability: short, agreed-upon labels

Group 2:

See color chip

Select that color from array of colors

Memory better for more codable colors


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Codability of color predicts memoryBrown & Lenneberg

Group 1: codability: short, agreed-upon labels

Group 2:

See color chip

Select that color from array of colors

Memory better for more codable colors

BUT: didnt test across languages


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Codable colorsBerlin & Kay, De Valois

Likely to be prototypical colors across languages

Languages differ on color boundaries, not centers

Visual system especially sensitive to prototypical

colors


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Teaching color & shape names to Dani

Rosch

No names for colors or shapes; taught names

Easy to learn prototypical colors, shapes

Hard to learn peripheral colors, shapes


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Whorf Hypothesis: 2 strikes against

Colors (shapes) that are highly codable are

Central members of categories

Remembered/learned better across cultures

Perhaps these categories are universal

But, hold on.not out yet


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Define:

Vegetable

Table

Vehicle

Cup


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Rate how good each exemplar is of

category:FRUIT: pineapple, grapes, persimmon, apple

VEHICLE: bus, jeep, skateboard, car

FURNITURE: clock, table, couch, ottoman

CLOTHING: belt, shoes, shirt, pants


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Write examples of the following

categories:

Odd Number

Color

Musical instrument

Emotion

Tool


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Horizontal organization of categories

Definitions arent good

Boundaries arent good

Agreement on good examples, focal cases:

Prototypes


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Horizontal, internal structure of

categories Family resemblance

Set of characteristic features No one member has all the features

Prototypical members have more of the features


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Horizontal, internal structure of

categories Family resemblance

Set of characteristic features No one member has all the features

Prototypical members have more of the features

Furniture: legs, seat, back--chair, couch, not rug

Fruit: sweet, seeds, small--apple, not watermelon


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Cognitive tasks supporting typicality

Verification RT: faster to say yes to car is

vehicle than skateboard is vehicle

Development: typical learned earlier Production: typical produced earlier

Language: typical more frequently used


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Structure of categories

Vertical: basic level is privileged/neutral

Horizontal: think of categories in terms of Typical examples

Family resemblance

Rather than necessary and sufficient features


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Whorf Hypothesis: Act III

Levinson

Some widely dispersed languages dont use left

and right to describe locations; use NSEW


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Levinson



Task Study parade of animals, aardvark.giraffe.zebra

Order mixed up, participant turned 180 degrees

Put animals in order


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Levinson






Results

Speakers of R/L languages line up animals L/R

Speakers of no R/L languages line up animals NSEW


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Levinson






Results

Speakers of R/L languages line up animals L/R

Speakers of no R/L languages line up animals NSEW

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