Combining Prototypes: A Selective Modification Model

We propose a model that accounts for how people construct prototypes for composite concepts out of prototypes for simple concepts. The first component of the model is a prototype representation for simple, noun concepts, such as fruit, which specifies: (1) the relevant attributes of the concepts, (2) the possiblevalues of each attribute, (3) the salience of each value, and (4) the diognosticity of each attribute. The second component of the model specifies procedures for modifying simple prototypes so that they represent new, composite concepts. The procedure for adjectival modification, OS when red modifies fruft, consists of selecting the relevant attribute(s) in the noun concept (color), boosting the diognosticity of that ottribute, and increosing‘the salience of the value named by the adfective (red). The procedure for odverbiol modification, OS in very red frutt, consists of multiplication-by-a-scalar of the salience of the relevant volue (red). The outcome of these procedures is a new prototype representation. The third component of the model is Tversky’s (1977) contrast rule for determining the similority between a representation for a prototype and one for on instance. The model is shown to be consistent with previous findings about prototypes in generol, OS well as with specific findings about typicality judgments for adjective-noun conjunctions. Four new experiments provide further detailed support for the model.