The Army needs a distributed training environment that can be accessed whenever and wherever required for training and mission rehearsal. This paper describes an experiment to investigate the effectiveness of a prototype of such a system, using mixed reality (MR) presented by the Battlefield Augmented Reality System (BARS), a mobile augmented reality system with a wearable computer, and see-through head mounted display (HMD). The users' positions were tracked wirelessly, while a graphic representation of their virtual surroundings was displayed on the HMD as they walked. Previous studies have shown virtual environments can be used to train navigation. The addition of natural movement to a type of virtual environment may enhance that training.

Sixty participants were randomly assigned to three conditions and memorized directions for a route through a complex area. Participants in the map condition performed three rehearsals of the route by drawing on a printed floor plan of the environment. Participants in the walker condition executed three rehearsal traversals of the route in the actual facility. Those in the MR condition did the same wearing the BARS system which provided a realistic environment, with landmarks, waypoints and virtual footprints. A scaling factor was used, with each step in the MR environment equal to three steps in the real environment, and the environment was broken into "tiles", much like atlas pages. Participants worked their way through each tile in succession until they completed the entire route. Transfer of training results from testing in the real environment found a significant but weak difference between walkers and MR, and walkers and drawing for route knowledge, with walkers committing fewer errors while completing the route more quickly. No differences were found among any of the conditions for survey knowledge. There were no symptoms of simulator sickness among the MR participants of this study.