Concept maps Flashcards
Classical theory of categorization
Prior history
- Disjunctive concpets (which require at least 1 attribute is present), which are the rarest are also the hardest to learn
Classical theory of categorization
Main claim
Categories are defined by a set of features that are individually necessary and jointly sufficient for category membership
Classical theory of categorization
Competing theory and how it differs
- Prototype theory - the set of features are characteristic and not defining
- Explains the typicality effect
Classical theory of categorization
Data undermining the theory
- People agree that cars seats are chairs, whcih are furniture, but car seats are not furniture
- The Typicality effects
Classical theory of categorization
Major weakness
- It is impossible to define the necessary and sufficient features for some categories
- Strict hierachy doesn’t always exist
Classical theory of categorization
Similar theory and one of its features
Essentialism: Both theories state that there are immutable characteristics that define a category and those features are not dependent on context
Classical theory of categorization
2 characteristic features
- Category membership is binary
- Concpets can be organized in a hierachy of inclusion relations
Exemplar/instance-based theory
Prior history
Prototype theory
Exemplar/instance-based theory
Main claim
Category membership depends on similarity to a set of stored exemplars
Exemplar/instance-based theory
Competing theory
Classical theory - Does not depend on similarities but specific features that have to be present
Exemplar/instance-based theory
Data supporting the theory
- Participantssay more often that a 18-inch object is a pizza than a ruler because rulers usually don’t vary in size but pizzas do
- A prototype would be insufficient because both have the same average size
Exemplar/instance-based theory
Major strenght of the theory
Can explain typicality effects
Exemplar/instance-based theory
Similar theory and one major feature
Prototype theory: Both theories state that categorization is based on similarity
Exemplar/instance-based theory
2 characteristic features
- Many exemplars for each category are stored in memory
- Objects are matched in parallel with all stored instances to compute similarity
Protoype theory
Prior history
Classical theory
Protoype theory
Main claim
Category membership depends on similarity to a prototype, which is the most typical member of the category
Protoype theory
Competing theory and how it differs
Classical theory: Assumes binary category membership
Protoype theory
Data supporting the theory
- Objects more similar to the prototype get identified faster
- People tend to list characteristics, not defining features, of categories
Protoype theory
Major weakness
- Some abstract concepts do not show prototype structure
- The theory assumes people use only fairly superficial features, but they may use more central ones instead
Protoype theory
Similar theory and major features
Exemplar-based theory: Both theories state that categorization is based on similarity
Protoype theory
2 characteristic features
- The features of a prototype are characteristic, not necessary
- Category boundaries are fizzy, not absolute
Explanation-based theory
Prior history
Exemplar-based theory
Explanation-based theory
Main claim
To categorize objects, people use common-sense explanations, motivated by their intuitive theories about the world
Explanation-based theory
Data suporting the theory
- The Dyirbal aboriginal tribe classifies nouns into meaningful categories, which are neither rule- nor similarity-based. They are knowledge based