This paper describes the role of simulation-based training in the military. Interviews and observations
of military instructors in the damage control and shiphandling domains provide examples of how the instructors
extend the student’s training beyond the well-defined simulated world with qualitative reasoning about context,
hypothetical variants, and critical factors of the scenario. An intelligent tutoring system for a simulator can have
a well-defined core area of domain knowledge, but to replicate more of the human instruction typically given in
simulation-based training, the ITS should include a capability to deal with the ill-defined periphery of domain
knowledge. Natural language interaction, including asking students open-ended questions about their
performance, can help support tutoring of the ill-defined material.