His high-level research goal is to build and study systems that leverage people’s online behavior to improve both individual and social outcomes. He has done such work in a number of domains, including modeling information dissemination in social media, supporting civic participation online, using social media content to support reminiscence and reflection, helping people contribute to public goods such as Wikipedia, and improving recommender systems. Much of the work has been supported by NSF and is rooted in the PhD in computer science he received in 2006 under the guidance of advisors John Riedl and Loren Terveen from the University of Minnesota.