Presentation at multi.player 2011 by Johanna Bertram (Knowledge Media Research Center Tübingen). Full title: "Learning in virtual environments: The role of social presence for virtual team training".
They designed some training for a police team, aiming to help co-ordinate helicopter, car and foot police. This isn't something they can practice in real life, as running the helicopter costs a lot and there is a lot of inconvenience for local people who want to know why the helicopter is around. It is important though, because helicopter pilots need to know how to best direct the ground crew, and the group on the ground need to understand what the helicopter pilots can or can't see and help them with. The virtual environment has the additional plus of allowing people to swap roles, without having to go through extensive retraining programs first!
They worked with experts to get some clear learning objectives, and to make sure they had the views they were giving the trainees correct. They actually initially had the views showing everything too clearly, which would have given a false impression of how much the helicopter crew could see and help. They also use simulated speech if you are close enough to someone for that to be an option, and if not they used simulated radio.
They used social presence research to ensure that people felt they were operating as part of a team within the virtual environment. It looked like it would be an effective learning tool, but the only feedback she gave was that the trainees who played video games had fewer problems with it than those who didn't. It may be too early in the process to tell. Looked like quite a promising use of the technology though.