L14 - Beyond the classical approach Flashcards
Concepts and categories can be used interchangably
But what is the technical difference between a category and a concept?
Categories are classes of objects in the world
Concepts are mental representations of the categories
How does the empirical evidence suggest that our concepts are mentally represented?
As distributing overlapping features or properties
How does the emipirical evidence suggest that our boundaries are defined?
They are “fuzzy” and not clear cut
Does the empirical evidence suggest that each member represents the category equally?
No
Some category members are more typical (better) than others for representing the category
Categories have what type of category structure?
graded category structure
What does graded category structure mean?
Some members of categories have higher typicality ratings than others.
Some members are more typical of the category than others
Which category model best describes the graded category structure?
Family Resemblance Model
Which measure was used in the Rosch & Mervis (1975) measure to show graded category structure?
Family Resemblance measure
A weighted measure of featural commonality amongst category members
“The more similar an exemplar is to other category
members …. the higher its family resemblance, and the
more typical it is of its category” (Barsalou, 1985, p. 630).”
What is the relationship between typicality and family resemblance for natural categories (e.g. fruits, vegetables, mammals)
Who foudn this correlation and based which theory off of it?
Strong correlation between typicality and family resemblance
Rosch - Family Resemblance model
the graded typicality structure that we see in the categories is well described by the ______________ of the category members
featural overlap
Who theorised The Polymorphous Concept Model ?
Hampton (1979)
What does The Polymorphous Concept Model propose?
The representativeness of an exemplar is a function of the degree of overlap between the features associated with the exemplar and the features associated with the category
In Hampton’s (1979) study, what is a good predictor of ‘typicality ratings’ and generation frequencies of category members?
‘representativeness’ ratings
What is the similarity of the The Family Resemblance model and the
Polymorphous Concept model?
both use featural overlap to measure graded category structure
The graded structure of categories can be reflected by -
typicality and generation frequency
What did Ashcraft (1978) and McClosky (1980) suggest could be responsible for the differences in typicality?
Familiarity
They suggested that differences in typicality may be due to how familiar people are with the category member
What interesting finding regarding “titmouse” was found in the Hampton (1979) study?
What does this imply?
Despite looking like a very typical bird, it was only “just included” in the bird category
Implies that familiarity with the category member plays a part in category experiments
In Hampton (1983) followed up on familiarity by measuring two measures associated with graded category structure (typicality and generation/associative frequency) plus familiarity.
What results did he find when using partial correlations?
(Looking at the relationship between two things while holding the other one constant - removing the shared variance)
There is something that is shared with typicality and associative frequency that is not shared with familiarity
When you remove familiarity there is still a strong correlation, but not when familiarity is inlcluded
What sort of tests can you use to generate similarity data?
Describe the Tversky’s (1977) Contrast Model regarding how similarity is calculated
The Family Resemblance Model and Polymorphous Concept model of a special form of which model?
The Contrast Model (Tversky, 1977)
What does our spatial representations that are generated using MDS reflect about us?
Reflects the structure of the categories that are being represented
e.g. our mental representation of colour is a wheel
Physical properties are reflected in our mental representations.
True or false
True
Physical properties are reflected in our mental representations
Spatial representations generated using MDS appear to reflect the structure of categories that are being presented in perceptual data and _______ data
important
conceptual data
- we can see that similar animals are in similar in space due to category membership*
- (domesticated at top, large bottom right etc.)*
What is meant by “the spatial structure of the categories is readily interpretable” in MDS data?
Looking at visual MDS data we can determine which members belongs to which category
- This happens without us asking them to represent it this way - similarity plays a big part*
- e.g. fruits (right) and vegetables (left), halfway fruits/veg are in-between*
What are additive tree structures?
Additive trees represent category members as terminal nodes in a tree,
such that the similarity of two group members is the length of the branches separating them in the tree …
How has similarity been criticised
- Similarity is not flexible enough
- Similarity is too flexible
Summary Slides
Good luck!
