ABSTRACT
This chapter reviews strong evidence that exists for three general forms of expression effects: public release of message can commit the sender to what they expressed, the act of organizing thoughts into one's own words can alter or integrate sender's understanding, and the expectation of possible future expression can affect attention to and processing of received messages. It then explores how these general forms of expression effects could inform theorizing about potential impacts of new media on two democratically important outcome variables: citizen competence and political participation. After situating expression effects by distinguishing between two levels of communication models, and after a review of the empirical evidence for expression effects in general as well as in new media contexts. The chapter then explores implications of expression effects for new media and map out program of future research. In order to clarify difference between expression effects and feedback, to distinguish between two levels of communication models: message effects and communication processes.
