Military and personnel training research addressing individual differences in training environments appears in four general research areas. These include the study of (1) trainee cognitive strategies, learning styles, and sensory modalities; (2) noncognitive characteristics of trainees; (3) aptitude-performance interactions; and (4) the effects of instructional methods. Although the areas do overlap, the major distinction is that the first two are concerned with variables or factors that individuals bring to the training environment, whereas the final two address the issue of how to accommodate the training process to individual trainees. Within each of these four areas, the research supports the view that individuals are affected differentially by training and that these differences need to be incorporated into the training process. A proposed model for determining instructional strategies provides a means for accommodating individual differences relevant to the training environment. This decision model for training program design involves classification of training tasks, selection of personnel for training, and specification of instructional strategies for optimal learning. (A reference list is appended.) (YLB)