  Collaborations such as Wikipedia are a key part of the value of the modern
Internet. At the same time there is concern that these collaborations are
threatened by high levels of member turnover. In this paper we borrow ideas
from topic analysis to editor activity on Wikipedia over time into a latent
space that offers an insight into the evolving patterns of editor behavior.
This latent space representation reveals a number of different categories of
editor (e.g. content experts, social networkers) and we show that it does
provide a signal that predicts an editor's departure from the community. We
also show that long term editors gradually diversify their participation by
shifting edit preference from one or two namespaces to multiple namespaces and
experience relatively soft evolution in their editor profiles, while short term
editors generally distribute their contribution randomly among the namespaces
and experience considerably fluctuated evolution in their editor profiles.
