Is it possible at present to identify a core cluster of theoretical ideas, concepts, and methods with which everyone working in the area of learning and cognition needs to be familiar? Would it be possible to make explicit the relationships that we feel do or must exist among the various subspecialties, ranging from conditioning through perceptual learning and memory to psycholinguistics, and to present these in a sufficiently organized way to help specialists and non-specialists alike in relating particular lines of research to the broader spectrum of activity? These questions were posed to a substantial number of investigators who were most active in developing the ideas and doing the research in the early 1970s. Originally published between 1975 and 1978, their response constitutes this 6-volume Handbook of Learning and Cognitive Processes. The volumes survey the research and theory on learning and cognitive processes that were rapidly developing at the time. The primary orientation was to concentrate on research and models aimed toward the development of general cognitive theory. They were up-to-date with regard to theoretical and technical developments, and sufficiently self-contained to be readable by anyone with a reasonable scientific background, regardless of their acquaintance with the technical jargon of particular specialties. Previously out of print, the Handbook is now available again, as a set or as individual volumes.