Date of Award


Degree Name

Doctor of Philosophy


Mass Communication and Media Arts

First Advisor

Lowry, Dennis


This study first tests the factors influencing the willingness to express opinions online. Guided by the spiral of silence theory, the research used a survey to test whether fear of isolation and opinion congruency work online. Second, the study explores how psychological constructs, including self-efficacy, collective efficacy, and proxy efficacy affect the willingness to express disagreement. A 2 × 2, verbal persuasion × vicarious experience, experiment was applied. Third, this study also conducted a content analysis to measure disagreement expressions in online newspapers and test how these expressions affect opinion quality and online discussion involvement. The survey study (N=321) showed that while fear of isolation online negatively predicts the willingness to express individual opinions, opinion climate congruency is not associated with the willingness. The online experiment demonstrated that mastery experience and verbal persuasion positively influence self-efficacy, but vicarious experience's effect was not confirmed. Self-efficacy plays the most salient role in predicting whether one selects to express disagreement online. The content analysis (N=1,288) of the discussion threads demonstrated that disagreement expression is widespread in the online newspaper forums analyzed, and such expression positively influences reasoned opinions and political discussion engagement.




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