The communication environment in CMC is particularly relevant to the discourses of the traditional communication theory, spiral of silence. This paper embarked on the task of developing an experimental research method to test willingness to speak out in the spiral of silence theory on an online forum and to test subsequent attitudinal and behavioral changes as measured in issue position, climate of opinion perception, and message posting. A 2x2 factorial design (congruent messages vs. incongruent messages and anonymity vs. nonanonymity) tested the willingness to speak out on an online discussion forum. The result of the paper suggested a new theoretical framework, selective posting, and called for the modification of the psychological explanation of spiral of silence.