This January we will be presenting a paper that analyzes the question (on Stack Overflow) of whether you are more likely to get a badge if your friends do. We found that there is a small influence, but it isn’t substantial. Here is a more complete abstract:
Badges can provide a number of advantages to networked, self-directed learners, including making visible social networks of support and direction. If badges do allow for this, we would expect to see badge acquisition to be predicted by the presence of a particular badge among a learner’s social connections. In examining the badges and “tags” used on the question-and-answer site Stack Overflow. We find that the more general badges are closely related to tenure on the site, while the numerous “tag” badges provide for more socially-determined differentiation.
And a PDF pre-conference version of the paper is available.