Simple Feature Frequency versus Feature Validity Models of Formation of Prototypes

Abstract

The typicality of a concept instance is related to the frequency with which its constituent features occur among all instances of the focal concept and possibly of other contrasting concepts. According to a simple frequency model, the prototype consists of the features that have occurred most often among instances of the focal concept. But according to a validity model, the prototype has the features that have occurred frequently among focal instances and, at the same time, infrequently among instances of contrast categories. By this account, the extent to which features overlap among focal and contrast instances is important in prototype formation. Here the feature frequencies among focal instances and the degree to which these features overlapped with contrast instances were manipulated. Twenty undergraduate college students first studied instances of the contrast category and then instances of the focal category. Next, they provided typicality ratings, frequency estimates of whole stimuli, and frequency estimates of features. All three measures supported the prediction of a simple frequency model of prototype formation.