Wikipedia
I've completed several projects on Wikipedia. One is a study of user contributions
looking at differences between user contributions in 2002 and 2005. During this time
period, Wikipedia had immense growth (from several thousand to several hundred thousand). We
were interested in learning how the community contributions change when the community
grows dramatically.
I also worked with a team to study both the creation of value in Wikipedia and the destruction of value
in Wikipedia (damage and vandalism). Very few studies had been done on this aspect of Wikipedia, so
we were quite excited to study it. We had some amazing results which can be found in Creating,
Destroying, and Restoring Value in Wikipedia. The paper can be found through the ACM Digital Library. I'll
have a local copy up shortly.