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.

We often think of communities as organic creatures, which come into existence and grow on their own. However, the truth is they are fragile blossoms. Although many communities surely germinate and bloom on their own, purposefully creating communities can take a tremendous amount of hard work, and one factor their success ultimately depends upon is their numbers. If a community is too small you'll often have insufficient critical mass to sustain it.