This paper presents findings from a cooperative research effort between the Center for Applied Psychological Studies of Old Dominion University, Norfolk, VA, and the Naval Training Systems Center, Orlando, FL. These studies of Team Evolution And Maturation (TEAM) are designed to investigate the development of teamwork during the training of operational Navy teams. Initial results are summarized in terms of a general model of the phases of team evolution and maturation, a "developmental" research perspective based on this model, prototype procedures for measuring team development during training, and data which provide empirical support for the model and measurement procedures. In addition, findings are presented which help to explicate the instructional strategies and processes employed in team training. The implications of these studies are discussed and recommendations are given concerning interventions for improving team training instructional technology.