KNOWLEDGE, SIMILARITY, AND CONCEPT-FORMATION

This article briefly reviews two recent lines of research that investi gate the role of background knowledge in category learning and categor y formation. The results of several experiments show that when subject s are able to use their background knowledge to integrate the features of instances with respect to an underlying theme, they learn the cate gories being taught by the experimenter much more easily. In addition, the opportunity to apply background knowledge dramatically affects wh at categories the subjects spontaneously form when they do not receive feedback from an experimenter. The implications of these results for traditional accounts Of similarity in category learning and formation are discussed.