This program identified applications and developed design characteristics for generalized training devices. The first of three sequential phases reviewed in detail new developments in Naval equipment technology that influence the design of maintenance training devices: solid-state circuitry, modularization, digital technology, standardization, functional packaging, general-purpose displays, computer aiding, automatic test equipment, lifetime spares design, life-cycle costing, and total system design. In the second phase, three generalized training devices were recommended for development: 1) a digital systems training device, 2) a communications system training device, and 3) a generalized torpedo maintenance training device. In the third phase, the design and use characteristics of each of the three devices were developed, with emphasis on the digital systems device. Each of them was developed to the functional block diagram level. On the basis of these studies, recommendations are made for the inclusion of computer-assisted instruction techniques as they relate to the digital systems trainer. (Author/JK)