Prototype

The prototype or family resemblance view (Rosch & Mervis, 1975; Rosch, 1978) is one of five theories of conceptual structure in categorization (Komatsu, 1992). According to this view, people form summary representations - prototypes - that abstract across specific instances (e.g. several chairs) to give information about how members of the category, on average, are like. Other theories of conceptual structure are the classical view (Katz, 1972; Katz & Fodor, 1963), the exemplar view (Medin & Schaffer, 1978), the schema view and, most recently, the explanation-based or theory view (Johnson-Laird, 1983; Murphy & Medin, 1985).

Characteristics of the prototype view are:

Centrality of typicality: Items with greater family resemblance to a category are judged to be more typical of the category.

Abstractness: The information contained in a prototype is an abstraction across several instances of the concept.

Weighted attributes: If the combined weights of a novel object's attributes' relevance for conferring family resemblance to the category exceed a certain level (the mebership criterion), that object will be considered an instance of the category (Medin, 1983).

Linear separability: The method typically used to combine the attribute weights was adapted from Tversky's (1977) contrast model of similarity. The attribute weights are assumed to be independent and combined by adding (that means they are linearly separable).

Retention of central tendencies: A concept provides a summary of a category in terms of the central tendencies of the members of that category rather than in terms of the representations of individual instances (which is the exemplar view).

Literature: Barsalou (1985), Camerer (1997), Johnson-Laird (1983), Katz (1972), Katz & Fodor (1963), Komatsu (1992), Medin (1983), Medin & Schaffer (1978), Murphy & Medin (1985), Rosch & Mervis (1975), Rosch (1978), Tversky (1977)

Entry by: Ulf-Dietrich Reips

June 7, 1999 Direct questions and comments to: Glossary master