The Infantry Immersive Trainer (IIT) is a mixed-reality training system designed to extend training capabilities for Marines across a wide range of military operations (ROMO) within a single training environment. This is accomplished with a cutting-edge mix of real and virtual technologies, with a configurable hardware and software system infrastructure, allowing training scenarios to be quickly modified to focus on different training objectives based on an incoming trainee group's specific needs and goals.

In this paper, we review our lessons learned in developing scenarios for this mixed-reality environment, In addition to traditional scenario design challenges, the experience involved new challenges focusing mainly on maintaining a realistic experience at locations where the physical system and the virtual system converged. Also, the effort involved using front end analysis to drive scenario design, early in the system development cycle, providing the opportunity for scenario design to inform the configuration of physical and virtual capabilities to support increased training value and modularity. Finally, we present a summary of our results of an initial theoretical training effectiveness evaluation for the whole system, which provides additional insights to the scenario design and system development process. We conclude with a recommended approach for future mixed-reality scenario design efforts.