How might you describe the different "people" in this room:
Real people and avatars? Coaches, students, and characters? Teammates and competitors? Buddies? Colleagues? Leader and followers?
A challenge in discussing educational simulations is that the same person has different roles, depending on if you are looking at the context of the virtual world, the classroom, and the real world. For example, the same person can be a hero in the context of the sim, a student in the context of the class, and a project manager/steward in the context of the enterprise.
Likewise, coach can refer to an embedded, pre-scripted avatar and/or a real person.
Characters in the sim can only exist in the sim, or be controlled by other students. A colleague of yours (context: real world) can help you either by being a teammate (context: virtual world) or a buddy (context: classroom). (The difference being a teammate helps you in the sim, a buddy helps you understand the sim.)
It is further interesting to note what a simulation adds to the more traditional concept of a role-play.
Productive comparisons and best practices require a common vocabulary. I have working definitions of all of these role, but here's a first draft at a chart to put it all together.
As always, I would appreciate any feedback.