The problem of operational user acceptance of naval training R&D studies and training devices is presented. A number of constraints on acceptance are described, including deficiencies in motivational conditions, deficiencies in social role assignments, deficiencies in official organizational policy and structure, inadequate defense R&D contracting methods, lack of integration of the user into the trainer system acquisition process, other-than-rational user responses to R&D studies in training, and deficiencies in training device design. A preliminary model of the acceptance process is presented. Finally, the degree of physical fidelity necessary for operational acceptance and training effectiveness is discussed. It is concluded that this paper and related recent work form a basis for the development of alternative approaches to solving the user acceptance problem.