Chronometric analysis of classification.

This series of studies represents an effort to extend the subtractive method of Bonders to the analysis of depth of processing in simple classification tasks. The stimuli are always pairs of items (letters, nonsense forms, digits) to which S must respond "same" or "different" as quickly as possible. Levels of instruction are physical identity (e.g., AA), name identity (e.g., Aa), and rule identity (e.g., both vowels). By use of the subtractive method, times for matches at each level are analyzed. The emphasis is not placed upon the times themselves but upon their relevance for understanding the operations and mechanisms involved in perceptual matching, naming, and classifying.