First published in 1984. The effects of contextual stimuli on the performance of conditioned behaviors have recently become the object of intense theoretical and empirical scrutiny. This book presents the work of researchers who have attempted to characterize the role of context in learning through direct experimental manipulation of these stimuli. Their work reveals that context has important and systematic effects upon the learning and performance of conditioned responses. The roles played by context are diverse and the problems confronted in attempting to evaluate and differentiate contextual functions are formidable. These considerations are discussed in the introductory chapter. The remaining chapters present an analysis of the role of context in Pavlovian, operant, and discrimination learning paradigms.