I suggest that perceptions of diversity and disagreement voiced in the on-line political discussion may play a key role in mobilizing citizens to voice their views and take action in authoritarian regimes. The empirical focus is the Chinese Internet. Subjective perceptions of group discussion among participants can significantly differ from the objective content of the discussion. These perceptions can have an independent effect on political engagement. Novel is also that I will study which technological settings (blogs, Weibo (Twitter), public hearings, etc) facilitate these perceptions.I will address these novel issues by specifying the conditions and causal mechanisms that facilitate the rise of online public opinion. As an expansion to prior work, I will study passive in addition to active participants in online discussion. This is of particular interest because passive participants outnumber active participants.My overall aim is to deepen our knowledge of how participants experience online political discussion in stabilizing or destabilizing authoritarian rule. To this end, I propose to work with one post-doc and two PhD research assistants on four objectives: Objective 1 is to explore what kinds of people engage in online discussions and differences between active and passive participants. Objective 2 is to understand how the technological settings that create the conditions for online discussion differ from each other. Objective 3 is to assess how active and passive participants see the diversity and disagreement in the discussion in these settings. Objective 4 is to assess whether citizens take action upon online political discussion depending on how they see it.I will produce the first nationally representative survey on the experiences of participants in online political discussion in China. In addition to academics, this knowledge is of interest to policy-makers, professionals, and journalists aiming to understand authoritarian politics and media