  The Wikimedia Foundation has recently observed that newly joining editors on
Wikipedia are increasingly failing to integrate into the Wikipedia editors'
community, i.e. the community is becoming increasingly harder to penetrate. To
sustain healthy growth of the community, the Wikimedia Foundation aims to
quantitatively understand the factors that determine the editing behavior, and
explain why most new editors become inactive soon after joining. As a step
towards this broader goal, the Wikimedia foundation sponsored the ICDM (IEEE
International Conference for Data Mining) contest for the year 2011.
  The objective for the participants was to develop models to predict the
number of edits that an editor will make in future five months based on the
editing history of the editor. Here we describe the approach we followed for
developing predictive models towards this goal, the results that we obtained
and the modeling insights that we gained from this exercise. In addition,
towards the broader goal of Wikimedia Foundation, we also summarize the factors
that emerged during our model building exercise as powerful predictors of
future editing activity.
