Explain the design of Allen and Brooks' (1991) study which demonstrates the role of exemplars and rules in category learning. What were the findings?

Explain the design of Allen and Brooks' (1991) study which demonstrates the role of exemplars and rules in category learning. What were the findings?

The simplest structures that category knowledge contais are memories of individual category members; these are known as exemplars.

A rule-that is, a precise definition of the criteria for a category.

For example is a particular animal a builder or digger: ''An animal is a builder if it has two or three of the following properties: long legs, angular body, spots; otherwise it is a digger''. Allen and Brooks (1991) suspected that even though participants knew a rule fot the categories, they might nevertheless be storing exemplar memories and using them in categorization.

The study:
Training-Known Builder and Known Digger
Test-Positive Match (Builder) and Negative Match (Builder)
Explenation: In the training condition participants where provided with builder and digger to learn the rule for builders. In the test a positive match was a builder that differed only by one property from a builder studied earlier; a negative match was a builder that differed only by one property from a digger studied earlier. ''If participants use only rules to categorize builders, the positive and negative matches should be equally easy to categorize, given that both have two of the three builder properties. Alternatively, if participants also use exemplars to categorize builders, the negative match should be harder to categorize because it is similar to a member of the wrong category''.

The results of the study show that, depending on the training conditions, we acquire exemplar memories, rules, OR BOTH for the categories we learn. The results of the brain scans also show when ''participants did not know a rule, they primarily used visual memories of exemplars to categorize''.