The first important distinction between operant and Pavlovian conditioning was made in 1928 by Polish scientists Konorski and Miller. Unaware of their work, Skinner proposed a similar analysis in 1935 of the manner in which operant and Pavlovian conditioning might differ and interact. Konorski and Miller responded to Skinner's statement, and by 1937 the now-classic debate over "two types of conditioned reflexes" was in high gear. In the years before publication, the attention of many learning theorists had returned to the fundamental question of whether there are identifiably different forms of learning. The present volume, originally published in 1977, contains chapters that reassess our basic learning paradigms of the time. They deal with the definitional problems of isolating operant and Pavlovian conditioning, as well as the attempt to analyze the inevitable interactions that follow. These issues are examined in a variety of settings: some authors deal with operant-Pavlovian interactions directly by devising procedures to generate them; others examine operant-Pavlovian interactions by examining their possible contribution to established conditioning paradigms.