Artifact category membership and the intentional-historical theory.

Bloom has illustrated a number of complex and interesting phenomena that must be accounted for by any theory of categorization. We agree with Bloom about several important points: that the intended function of an object alone does not account for its categorization; that historical relations among objects can be important in assigning category membership; and that a name bestowed upon an object by a prior source can be an important contributor to categorization of the object. We also agree that intention may enter into category judgments in some cases. Still, we believe that the intentional-historical theory falls short of providing a compelling general account of artifact category membership.

An on-line investigation of prototype and exemplar strategies in classification.

Although prototype- and exemplar-based models of categorization are very different in character, they have proved difficult to distinguish experimentally. The research described here presents a priming technique for assessing the type of information retrieved at the moment that a categorization decision is made. This technique avoids many of the problems inherent in the standard paradigms. Data from six experiments are presented that demonstrate the usefulness of the technique and also address basic questions about the categorization process. Results bolster previous suggestions that categorization strategies may be mixed within a single experimental task and highlight the need for more specific predictions about when each strategy will come into play.

Predicting features for members of natural categories when categorization is uncertain.

An important function of concepts to allow prediction of unseen features. A Bayesian account of feature prediction suggests that people will consider all the categories an object could belong to when they judge the likelihood that the object has a feature. The judgment and decision literature suggests that they may instead use a simpler heuristic in which they consider only the most likely category. In 3 experiments, no evidence was found that participants took into account alternative categories as well as the most likely one when they judged feature probabilities for familiar objects in meaningful contexts. These results, in conjunction with those of Murphy and Ross (1994), suggest that although people may consider alternative categories in certain limited situations, they often do not. Reasons for why the use of alternative categories may be relatively rare are discussed, and conditions under which people may take alternative categories into account are outlined.