Choice, similarity, and the context theory of classification.

Medin and Schaffer's (1978) context theory of classification learning is interpreted in terms of Luce's (1963) choice theory and in terms of theoretical results obtained in multidimensional scaling theory. En route to this interpretation, quantitative relationships that may exist between identification and classification performance are investigated. It is suggested that the same basic choice processes may operate in the two paradigms but that the similarity parameters that determine performance change systematically according to the structure of the choice paradigm. In particular, when subjects are able to attend selectively to the component dimensions that compose the stimuli, the similarity parameters may tend toward what is optimal for maximizing performance.