Better to have many opinions than one from an expert? Social validation by one trustworthy source versus the masses in online health forums

Online health forums offer many cues such as who evaluated a certain piece of information and how many users have assessed the contribution. These cues help information seekers to answer questions of trust, e.g. whom and which information to rely on. This study seeks to determine the effect of social validation on trusting online health information. Specifically we question how much an expert statement is valued compared to a strong in numbers opinion from an anonymous mass. We report a study that manipulated the social validation of medical statements within online forum posts in a 2 (quality cue: yes vs. no) × 2 (quantity cue: yes vs. no) within-subjects design (N = 78). Dependent measures were credibility of health statements and trustworthiness of the author. Results showed that forum users trust social validation by the masses (quantity cue) just as well as validation by an expert (quality cue). Nevertheless, they did not question how the masses' cue related to the actual correctness of the statement.