As information and communication technologies have diffused, scholars have turned attention to online informal political discussion and formal deliberation because of the importance of online political talk for constructing society and informing government policy. This chapter examines the research on both formal deliberation and informal discussion online, identifies the importance of this research area, signals its major findings, and examines key unanswered questions. Along the way it argues that more research is needed to understand why women and minorities are less likely to talk politics online; better conceptual clarity is needed about the phenomenon of interest; more experimental work is required to isolate the causes and