Cognitive Psychology - Concepts and Prototypes

Exemplar Approach

• A concept is represented by multiple examples, rather than a single prototype.
• These examples consist of actual category members, not abstract averages.
• Categorization involves comparing a new item to stored examples.

Prototype Approach

• Prototype: An average representation of the "typical" member of a category.
  • It includes characteristic features that describe what members of that concept are generally like.
  • It is essentially an average of category members encountered in the past, as illustrated by a prototype bird that averages the features of sparrows, robins, and blue jays.

Prototypicality

• High Prototypicality:
  • A category member closely resembles the category prototype.
  • It is considered a "typical" member of the category.
  • For example, a robin is a highly prototypical member of the "bird" category.
• Low Prototypicality:
  • A category member does not closely resemble the category prototype.
  • For example, a penguin is a low prototypicality member of the "bird" category.

Prototypicality and Family Resemblance

• A strong positive relationship exists between prototypicality and family resemblance.
• Items within a category that share a large amount of overlap have high family resemblance.
• Conversely, low overlap among items results in low family resemblance.

Typicality Effect

• Prototypical objects are processed preferentially.
  • Smith and coworkers (1974) found that highly prototypical objects are judged more rapidly.
  • Rosch (1975b) demonstrated that prototypical objects are named more rapidly.
• Prototypical category members are more affected by a priming stimulus.
  • For example, hearing "green" primes a highly prototypical "green" object.