2.1
Problem 4
Problem A
Form mental concepts of categories of objects
o Permit appropriate responses to new objects encountered
Objects fall into many different categories- set of objects that can be treated as
equivalent in some way
o Basic-level category- most salient category that is at an intermediate
level of specificity
Concepts closely relate to our knowledge of world, can learn things easier if they
are concepts consistent with their knowledge
Theories of concepts: either people learn a summary description of whole category, or
learn exemplars of category
Most categories are informative, sharing many properties
Objects in a given category are different from one another, but can have many
commonalities
Concepts- mental representations we form of categories
Assume concepts correspond closely to actual category but useful to distinguish
between the two, as when someone’s concept isn’t really correct
Concepts allow extension of what’s learnt about limited number of objects, to
potentially infinite set of entities
Traditionally, categories view as well defined- you can give a definition that specifies
what is in and out of the category
Two parts to well defined definitions:
1. Provides necessary features for category membership (what objects must
have)
2. Features must be jointly sufficient for membership (if object has those
features, it is in that category)
X – assumptions of well defined categories is not correct
Hampton Study
Method: asked students to judge if a number of items where in different categories
Results: items were not either clear members or clear nonmembers: many items were
barely considered category members, other barely just not members- formed a
continuum with no obvious break in people’s membership judgments
Borderline members- not clearly in or clear out of the category
McCloskey and Glucksberg
Method: asked people to judge category membership twice, separated by two weeks
Results: when people repeated category judgements, they changed their minds about
borderline items
Significance: people disagree with one another’s about borderline items as well as with
themselves
Fuzzy categories- unclear boundaries that can shift over time
Even among items that are clearly Ina category, some seem to be better
members than others
Typicality is most important variable in predicting how people interact with
categories
Category prototype- most typical category member
Items less similar to prototype become less typical
o At some point, become so atypical, start doubting if they’re in category at
all
Day to day may change mind on which category an atypical item is in
Changes in typicality lead to borderline items
Typicality Effects on Cognition
Judged category members more often
Speed of categorisation is faster for typical items
Problem 4
Problem A
Form mental concepts of categories of objects
o Permit appropriate responses to new objects encountered
Objects fall into many different categories- set of objects that can be treated as
equivalent in some way
o Basic-level category- most salient category that is at an intermediate
level of specificity
Concepts closely relate to our knowledge of world, can learn things easier if they
are concepts consistent with their knowledge
Theories of concepts: either people learn a summary description of whole category, or
learn exemplars of category
Most categories are informative, sharing many properties
Objects in a given category are different from one another, but can have many
commonalities
Concepts- mental representations we form of categories
Assume concepts correspond closely to actual category but useful to distinguish
between the two, as when someone’s concept isn’t really correct
Concepts allow extension of what’s learnt about limited number of objects, to
potentially infinite set of entities
Traditionally, categories view as well defined- you can give a definition that specifies
what is in and out of the category
Two parts to well defined definitions:
1. Provides necessary features for category membership (what objects must
have)
2. Features must be jointly sufficient for membership (if object has those
features, it is in that category)
X – assumptions of well defined categories is not correct
Hampton Study
Method: asked students to judge if a number of items where in different categories
Results: items were not either clear members or clear nonmembers: many items were
barely considered category members, other barely just not members- formed a
continuum with no obvious break in people’s membership judgments
Borderline members- not clearly in or clear out of the category
McCloskey and Glucksberg
Method: asked people to judge category membership twice, separated by two weeks
Results: when people repeated category judgements, they changed their minds about
borderline items
Significance: people disagree with one another’s about borderline items as well as with
themselves
Fuzzy categories- unclear boundaries that can shift over time
Even among items that are clearly Ina category, some seem to be better
members than others
Typicality is most important variable in predicting how people interact with
categories
Category prototype- most typical category member
Items less similar to prototype become less typical
o At some point, become so atypical, start doubting if they’re in category at
all
Day to day may change mind on which category an atypical item is in
Changes in typicality lead to borderline items
Typicality Effects on Cognition
Judged category members more often
Speed of categorisation is faster for typical items
