James - Sorry for not responding sooner to this. You are of course correct that context, content and other factors have significant impact on the "best" pedagogical approach to learning. We are currently working closely with two respected professors in the field - Carolyn Rose at CMU and Cindy Hmelo-Silver at Indiana. The three of us have jointly submitted a research proposal to the NSF to conduct further work in this area. What I am really trying to convey is that I think there can be an important role for real-time communication in the wiki context.