In recent work we’ve been leveraging community analysis methods to understand a real HAC – that of Massive Open Online Courses (MOOCS). To our surprise there are very strong patterns in the data, despite the users not collaborating and knowing one another. The community structure was reminiscent of the structure Edwin Simpson found when looking at large cohorts of users in Zooniverse. You can read more here: http://arxiv.org/abs/1403.4640