over distributed networks. For all levels of training, VEs can be used to safely provide exercises in hostile and dangerous environments. Moreover, in the future, computers will have the capability to generate VEs as replacements for and extensions of traditional equipment-bound simulators. A critical issue discussed in the training application section of this chapter is the problem of conducting evaluation studies that demonstrate the impact of one method or another on training success as defined by how well the knowledge and skills acquired in training transfer to performance on the job.
Of particular interest to DoD is the development of networking hardware and software for large-scale distributed training. The first large network simulation of realistic battlefield engagements was SIMNET, developed by DoD's Advanced Research Projects Agency. In SIMNET, as many as 300 soldiers in tanks and aircraft simulators located at different military bases can engage in a realistic battle against an intelligent enemy on a common battlefield. Each participant in the battle views the portion of the terrain and the action that would be visible to him if he were present. As a battle unfolds, the scene changes in real time. Once a battle is completed, it can be replayed as an after-action briefing in which trainees can zoom in on various portions of the engagement or take the perspective of any tank or aircraft.
More recently, DoD has used its newest software—Distributed Interactive Simulation (DIS)—to develop a detailed, true reconstruction of the 73 Eastings battle that occurred during the Persian Gulf war. This fully interactive simulation is based on the events in an actual battle; as a result, it can be used as a benchmark to examine what-if training scenarios when enemy or friendly weapon system capabilities are changed. The projections are that DIS will provide many of the networking capabilities needed by the military for both training and system acquisition.
The final chapter of this report provides a more detailed description of the use of SE technology for each of the application areas selected for review.