For the previous 6 years before publication, Office of Naval Research (ONR) had been conducting a thematically oriented contract research program aimed, in large part, at developing the kind of broad theoretical framework necessary for a workable process interpretation of aptitude, learning, and performance. Originally published in 1980, the papers in this collection are generally addressed to three broad areas that were central to those interests of the ONR Personnel and Training Research Programs. One area is concerned with individual differences information processing, as revealed in simple laboratory or psychometric tests. The second area focuses on the structural aspects of learning and performance, using tools and concepts from semantic memory theory to describe what is learned and how it is learned. And the third area is aimed at the management of instruction: It addresses itself to the kinds of research and instructional designs required for effective implementation of adaptive instruction.