lecture 8 - concepts and categorisation Flashcards
what is a concept
a mental representation useful for cognitive efficacy
what are the two types of concepts
- logical concepts
- natural concepts
what is categorisation
the process by which things are placed into groups
why do we categorise
- it reduces complexity of the enviro (cognitive economy)
- it allows us to recognise novel patterns
- allows us to establish hierarchy of objects
what is cognitive economy
reducing the complexity of the environment
what did roch provide evidence for in the natural categories
psychological privelage
what are the 3 levels of the natural categories as a hierachy
- global (subordinate)
- basic
- specific (subordinate)
explain the natural category - superordinate level
- highest level of abstraction
- consists of general categories
- consists of only a few attributes
- top level
- eg birds , furniture
explain the subordinate level of the natural category : as a hierachy
- lowest level of abstraction
- consists of specific types of objects
- consists of many attributes
- eg end of table, songsparrow
explain the basic level of the natural category : as a hierachy
- exists between the 2 extremes subordinate and superordinate
- is a balance between informativeness and economy (informativeness- of attributes the concept conveys )(economy - the summary of the important attributes)
- usually acquired first by children
- recognised more quickly by non experts
- eg table, sparrow
who usually aquires basic level hierachys first
usually first acquired by children
provide some evidence that Evidence that Basic-Level Is Special
- people almost exclusively use basic-lecek names in free naming tasks
- quicker to identify basic level category as a member of a category
- children learn basic level quicker than other levels
- basic level is much more common in adult discourse for superordinate categories
- different cultures tend to use the same basic level categories - at least for living things
how does basic level hierachys change within cultures
- different cultures tend to use the same basic level categories - at least for living things
what are the two types of characteristics proposed as occurring within a category
family resemblance
and
typicality
explain family resemblance characteristic
first proposed by Wittgenstein (1953)
is a continuous variable
is a measure of the overlap between members within a category
is measured by the number of shared attributes
how is family resemblance measured
is a measure of the overlap between members within a category
is measured by the number of shared attributes
explain typicality
refers to the differences in how well members relate to their category (e.g., collie vs. dachshund)
the higher the family resemblance the more typical the item is for common taxonomic categories
what happened in rochs experiment
- pps had to rate a list of words / objects
- judged on a scale of 1 (good example of a category ) to 7 (poor example)
rated birds and furniture
explain the The Defining-Attribute View to a concept
Frege (1952) said a concept can be characterized by a set of defining attributes
intension:
the set of attributes that define what it is to be a member of the concept
bachelor - (male, single, adult)
extension:
the set of entities that are members of the concept
bachelor - (every bachelor)
All of the attributes must be present
Assumes categories are clearly defined and rigid
Defining attributes vs. characteristic attributes
what did frege say that the the 2 sets of defining attributes of a concept are
intension:
the set of attributes that define what it is to be a member of the concept
bachelor - (male, single, adult)
extension:
the set of entities that are members of the concept
bachelor - (every bachelor)
exp;lain the Definitional Approach to Categorization
Determine category membership based on whether the object meets the definition of the category
Does not work well
Not all members of everyday categories have the same defining features
does the Definitional Approach to Categorization work
- doesnt work well
- not all members of everyday categories have the same defining features
- eg chairs - can be a sofa, arm chair, bean bag
what is the prototype view
Categorization occurs by finding the best prototype/TBC item match
what are the different types of prototypes
- average of all members
- a specific instance of the category
- a set of characteristic attributes
- regardless, the prototype is the most typical