Political dialog evolution in a social network

User comments posted on the Facebook walls of the two major 2010 California gubernatorial candidates were analyzed for their trends over a 22-month time period leading up to the election. Changes in content reflected an early emphasis on community building, establishment of common identity, and enthusiasm building with considerable dialog directed toward the candidates themselves. Later comments reflected a more outward turn toward other participants. The two communities of interest did not behave in exactly the same ways through time. Designers seeking to create socio-technical environments for political and civic engagement must face the fact that users' goals and activities change dynamically in response to the evolving characteristics of the group and external events affecting the group members. Implications for the design of "social affect" and "social intention" browsers are discussed.