Willemsen, L. M., Neijens, P. C., Bronner, F. E. (2012). The ironic effect of source identification on the perceived credibility of online product reviewers. Journal of Computer-Mediated Communication, 18(1), 16-31.

Abstract: This study posits that sources of online product reviews can induce differential effects on 2 dimensions of source credibility, perceived expertise and perceived trustworthiness. Study 1 shows that experts are perceived as having more expert knowledge, but at the same time as having less trustworthiness than laypersons, and vice versa. These opposing credibility evaluations suppress the effect of online source identification on readers’ attitudes toward online product reviews. Study 2 finds that these opposing credibility assessments only emerge when the expert status of the source is based on self-claims. When the expert status of the online source is based on peer ratings, the source is assessed as having both expertise and trustworthiness.
Keywords: source credibility, computer-mediated communication, social media, online product reviews, electronic word of mouth

Link: http://onlinelibrary.wiley.com/doi/10.1111/j.1083-6101.2012.01598.x/abstract