Originally published in 1976, Volume 3 of this Handbook deals primarily with conditions of acquisition, retention and forgetting, and the manner in which acquired information and motivation combine to determine performance. The organization of this volume can be understood in terms of four principal categories. The first category deals with general problems of methodology, the second and third with basic concepts arising from research on human learning and performance and the fourth with applications.Volume 1 presented an overview of the field and introduced principal theoretical and methodological issues that persistently recurred in the expanded treatment of specific research areas which comprise the later volumes. The areas traditionally associated with conditioning, learning theory and the basic psychology of human learning are treated in Volumes 2 and 3. The last three volumes will range over active lines of research having to do with human cognitive processes, at the time: Volume 4, attention, memory storage and retrieval; Volumes 5 and 6, information processing, reading, semantic memory, and problem solving.