The digital revolution has sparked a worldwide movement toward the use of simulators to enhance training and accelerate learning. As simulator-based training grows, the concern of trainers should increasingly turn to determining if effective training is taking place, rather than merely using simulators more extensively. We reviewed the simulator training literature to see just what literature exists as well as the effect simulation is having in terms of training effectiveness. The review concentrated on the literature from several different domains/perspectives, including the NASA space program, commercial aviation training, medical procedures training, and nuclear power plant operation training. The objective of the review was to focus on prototypical studies which showed utility in determining the effects of simulator-based training of highly complex tasks. Unfortunately, our review showed that little attention is being directed toward determining the effectiveness of these training devices and research on the effective tactics and strategies for utilizing simulation are almost nonexistent. We then put forward a brief explanation for the lack of motivation to assess simulator-based training, along with a plea to move forward in this area. Finally, we review a model, first outlined by Lewis (1996), for assessing the effectiveness of simulator-based training.