Date of Award


Degree Type


Degree Name

Master of Applied Communication Theory and Methodology



First Advisor

Bracken, Cheryl

Subject Headings



This study tests for a spiral of silence effect on Facebook using vaccination as the controversial topic. Participants were required to have a Facebook account and to log in to their account to participate in the experiment. The three experimental conditions were real Facebook posts containing a meme about vaccines and a comment thread, where the manipulation occurred. The anti-vaccination condition had mostly anti-vaccination comments (9 of 10); the pro-vaccination condition had mostly pro-vaccination comments (9 of 10); and the mixed condition had an equal number of pro- and anti-vaccination comments (4 pro and 4 anti). Participants could leave a comment on the Facebook post; commenting on the post and intentions to engage with the post were the two dependent variables. Results found no difference in commenting or in intentions among the experimental conditions. Vaccination attitudes did not predict commenting but did predict intentions. There were no interaction effects of condition and attitudes on either commenting or intentions. A total of six comments were made across all conditions. Most of the comments supported vaccines. Results indicate vaccination did not inspire strong enough attitudes to create a spiral of silence effect on Facebook in this experiment.