Instructional computing in psychology has become increasingly important to undergraduate and graduate curricula. Four modes of instructional computing, drill and practice, data generators, experiment simulators, and gaming, are described and illustrated with actual programs. Implications of recent developments in cognitive psychology for instructional computing are outlined. Factors in the design of high-quality materials are described, and problems and opportunities for publication and distribution are discussed.Although the original theme of the National Conference on the Use of On-Line Computers in Psychology began with a major emphasis on laboratory applications, there were, at the same time, developments in instructional computing and computer-assisted instruction (CAl) that were not emphasized at meetings during those early years. This implicit (and sometimes explicit) policy was appropriate, since many of the applications of computers to instruction were of the "traditional" drill-and-practice sort or skill-building programs popular at the time and the level of sophistication of such software was relatively low. Moreover, there often seemed to be a clear distinction between "laboratory" computing and "instructional" computing. Laboratory computing was the application of computers to the study of behavioral phenomena. The computers used by psychologists were often dedicated to a particular task (or paradigm), and often the only feasible instructional computing was training graduate students to use the computer system to conduct research. Sometimes faculty would take graduate (and even undergraduate) classes to their laboratories to observe the experimental procedures used or to participate in experiments, with the expectation that the experience would enhance the students' understanding of behavioral phenomena. However, there was seldom any attempt to integrate such laboratories into the curriculum. This may have been appropriate, in part because the laboratories were often externally funded research laboratories, and in part because the research conducted was often at the forefront of the field and it would be difficult and perhaps inappropriate to merge such specialized work into undergraduate curricula.Three factors worked to bring a gradual end to the dichotomy of research and instructional computing. First, significant advances were made in the standardization of interfaces, which made it possible to quickly and inexpensively interface a variety of devices to computers. Second, the decreasing cost of minicomputers and the introduction of microcomputers made the development of computer-based instructional strategies feasible, practical, and, most important, transportable between laboratories and institutions.Third, developments in cognitive psychology made the application of computers to instruction compelling as demonstrations of principles being studied in the laboratory.Here, I will cover two aspects of instructional computing. One aspect I have termed "modes of instructional computing" and the othe...