2- How do we Categorise? Flashcards
What are the three approaches in suggesting how we categorise?
Definitional approach, prototype approach, exemplar approach
What is the definitional approach?
The classical and traditional way of looking at how we categorise
What rules is the definitional approach based on?
Rules of necessary and sufficient features
What does it mean that the membership of a category is binary in the definitional approach?
It is or is not
Who’s research was in the definitional approach?
Shepard, Hovland and Jenkins
What did Shepard, Hovland and Jenkins study?
If we can form categories/concepts with necessary and sufficient conditions
What were the stimuli used by Shepard, Hovland and Jenkins?
A category from 8 objects determined by size, shape, and colour
What did Shepard, Hovland and Jenkins find?
Some category types of easier/harder to learn
What are the 4 issues with the definitional approach?
- Most categories in our memory tend to be loose and fuzzy
- Graded membership
- Family resemblance
- Approach is made by clear rules that can’t apply to everything
What is graded membership?
Some are more typical members of a category than others
What is family resemblance?
Category members typically share a set of common features, but not all common features are present in ALL members
What is the prototype approach based on?
Prototypes
How is a prototype defined?
As the average of all members
What type of member does a prototype define?
A typical member of a category
What does a prototype member look like?
Doesn’t necessarily look like any exact member
How is membership of a category determined?
By how the object is compared with the prototype of the category
How are there lower memory demands in the prototype approach?
Only a single prototype and characteristic features are stored
Why are some more typical examples of a category than others?
Due to their higher similarity to the prototype
What is the prototypicality effect?
Prototypical objects are judged faster and named first
What may categorisation sometimes depend more on than inherent prototypes?
Context
What can’t prototypes explain?
The flexibility in categorisations
What is the examplar approach based on?
Exemplars stored in our memory
What are exemplars?
Actual members of the category encountered before
What are objects compared to in the exemplar approach?
All examplars in our memory
Why are more typical objects classified faster?
Because they are similar to more exemplars
How can exemplars become more influential?
In different contexts
What advantage does the exemplar approach have over the prototype approach?
It keeps variability information that prototype models don’t maintain
How can atypical cases still be categorised in the exemplar approach?
Based on their similarity to some exemplars
What will be processed more slowly?
Less similar things
What is the main issue with the exemplar approach?
There’s a limit in how much we can process
Why do we have to sacrifice some information?
For other more important information
How are categories organised?
Hierarchical from more general to specific
What levels can things still be categorised?
At many levels of abstraction
What is stored in semantic memory according to the classic view?
Necessary and sufficient features
What is stored in semantic memory according to prototype theories?
The prototype
What is stored in semantic memory according to exemplar theories?
The particular exemplar
How is a category decision made according to the classic view?
By deciding whether the stimulus has the necessary and sufficient features
How is a category decision made according to prototype theories?
By comparing the similarity of the stimulus to the prototype
How is a category decision made according to exemplar theories?
By comparing the similarity of the stimulus to the examplar
Can the classic view explain graded membership, typicality effect, etc?
No
Can prototype theories explain graded membership, typicality effect, etc?
Yes
Can exemplar theories explain graded membership, typicality effect, etc?
Yes
When may definitions be more useful?
Early in learning of simple, well-defined categories
When may prototypes be more useful?
For categories with a clear central tendency or common features
When may exemplars be more useful?
Later in learning, and when variability is high within a category
