I was musing as I was preparing for next week's Intensive at BGI that I have 21 students in my class, an uncomfortable size. That's because it lies between a smaller size where good conversations naturally occur, and a larger size where you can take full advantage of different activities that work well for larger groups. I talk about this a bit in my Group Threshold and Dunbar Number posts, where I call the group threshold size of between 10 and 24 people the “Judas Number” nadir, or low point.