This study used an experiment embedded within a Web-based survey to examine the influence of contextual (i.e., face-to-face vs. online chat room discussion) and social-psychological factors on individuals' willingness to express opinions. In this experiment, respondents were asked whether they would be willing to express an opinion if they were placed in a face-to-face discussion group in one condition and in an online chat room discussion group in the other condition.

Sustaining cooperation among self-interested agents is critical for the proliferation of emerging online social communities, such as online communities formed through social networking services.