> The only thing missing from the traditional classroom learning cycle is the possibility of something being explained in a different way if the student is still having difficulty.

I believe Khan's "Coaches" are for just this purpose. I really think that this is one of the more ingenious parts of Khan Academy. In traditional education, there was very little opportunity for collaborative learning because the roles of student and teacher are so well defined.

The role of a coach can engender and empower a collaborative learning environment.