Stuart Geiger and I just presented some research at WikiSym on why Wikipedia articles are deleted through both the speedy deletion or “CSD” process, a unilateral process whereby administrators can deleted problematic articles without discussion, and the articles for deletions or “AfD” process whereby articles discuss whether articles should be deleted. You might imagine that the majority of CSDs are deleted because of spam or vandalism, but interestingly, we found that the majority (the blue chunk in the chart on the left here) are deleted because of they lack any ‘indication of importance’. We also found that the deletion process is heavily frequented by a relatively small number of longstanding users.

Our key findings include:

1. About half of all deleted articles from June ’07 to Jan ’11 were unilaterally deleted by administrators via the CSD process.
2. Surprisingly, spam, vandalism and patent nonsense make up only 8.00%, 5.69% and 5.36% of CSDs respectively, while the more subjective ‘No indication of importance’ makes up 38.47% of all CSD criteria.
3. With some outliers, AfD discussions have few participants, and those participants are overwhelmingly regulars to the process. 74% of all AfDs are made up entirely of users who have previously participated in an AfD, and 18% of all AfDs only have one newcomer. You can read more on the PDFs below but there’s also a lot of great research by other authors at WikiSym and on from the Wikimedia Foundation’s Summer of Research program.

Poster PDF |  Participation in Wikipedia’s Article Deletion Processes (WikiSym accepted poster research) PDF