Category breadth and the abstraction of prototypical information

Studied the abstraction of prototypical information and the development of category breadth or categories defined by low-level distortions from the prototype or by a mixing of distortion levels, using 72 undergraduates. In the uniform-low condition, low-level distortions were classified into 3 categories containing 3, 6, and 9 stimuli; in the mixed condition, an equal number of stimuli at each of 3 distortion levels was classified into categories of sizes 3, 6, and 9. Subsequent transfer to old, new and prototype stimuli was investigated immediately and after delays of 1 and 10 wks. The degree of positive transfer to new instances interacted with category size such that a mixing of distortions resulted in superior transfer for the categories defined by a larger number of stimuli; transfer was greater for the uniform-low condition only when the category was defined by 3 instances. The influence of category size was maintaind across the 10-wk delay for the mixed condition, and, overall, the mixed categories tended to resist deterioration following long delays better than categories defined by low-level distortions. (PsycINFO Database Record (c) 2006 APA, all rights reserved).