[jansho]

Interesting that you mentioned superstar tutors. Their classes tend to be large too, I've been to one that's close to a hundred pupils. A noticeable difference is that their sessions tend to be a lot more entertaining and emphasise on "tips and tricks" - not sure if school classrooms should follow the latter trend though.

It does show that it's possible to teach a large class effectively. Teaching talent makes all the difference, with technology to support it.