How much work should get done in meetings?

My principle for doing work in meetings is simple. The more people in a meeting, the more important it is that no work gets done. It is very expensive to ever have many people listening to serial monologues or single conversations among two or three of the many. Watching other people talk is a costly form of disengagement and as importantly, it significantly slows the tempo of action in the group. 

Ideally, work is done in triad groups of three. It can happen concurrently in a meeting or between meetings. Work done between meetings allows for necessary research, reflection, option growing and rich feedback gathering.

With this approach, what happens in meetings is organizing and responding to the work done in triads. We update our intentions, questions and sprints. Meetings are shorter and more productive. More gets done faster.