Health information, credibility, homophily, and influence via the Internet: Web sites versus discussion groups.

Despite concerns about online health information and efforts to improve its credibility, how users evaluate and utilize such information presented in Web sites and online discussion groups may involve different evaluative mechanisms. This study examined credibility and homophily as two underlying mechanisms for social influence with regard to online health information. An original experiment detected that homophily grounded credibility perceptions and drove the persuasive process in both Web sites and online discussion groups. The more homophilous an online health information stimulus was perceived as being, the more likely people were to adopt the advice offered in that particular piece of information.