+\item 2012-07-14. Almost Wikipedia: What eight early online
+ collaborative encyclopedia projects reveal about the mechanisms of
+ collective action. Wikimania 2012, George Washington University,
+ Washington, DC.
+\item 2012-07-12. Can can social awards create better wikis? Wikimania
+ 2012, George Washington University, Washington, DC.
+\item 2012-06-29. When peer production works: Learning from failures, to
+ improve collaboration. Wikipedia Academy. Freie Universität Berlin ,
+ Germany. (\emph{Keynote address})
+\item 2012-04-24. Is volunteer labor a ``fixed and finite'' resource?
+ Evidence from peer production. MIT Economic Sociology Working Group.
+\item 2011-11-02. Almost Wikipedia: What eight early online
+ collaborative encyclopedia projects reveal about the mechanisms of
+ collective action. Wikimedia Foundation, San Francisco, California.
+\item 2011-10-29. Almost Wikipedia: What eight early online
+ collaborative encyclopedia projects reveal about the mechanisms of
+ collective action. Conference on Digital Commons, Barcelona, Spain.
+\item 2011-10-28. Status, Social Signalling and Collective Action in a
+ Peer Production Community. With Aaron Shaw. Laboratory for Social
+ Research Seminar, University of California Berkeley.
+\item 2011-10-11. Almost Wikipedia: What eight early online collaborative
+ encyclopedia projects reveal about the mechanisms of collective
+ action. Luncheon Series, Berkman Center for Internet and Society,
+ Harvard University.
+\item 2011-07-01. Using Social Awards To Build Better Free Software \&
+ Free Culture Projects. With Aaron Shaw. Fórum Internacional
+ Software Livre, Porto Alegre, Brasil.
+\item 2010-11-17. Almost Wikipedia: What eight early online
+ collaborative encyclopedia projects reveal about the mechanisms of
+ collecdtive action. MIT Economic Sociology Working Group. % hidden