Online Reviews, Helpfulness Ratings, and Consumer Attitudes: An Extension of Congruity Theory to Multiple Sources in Web 2.0

In online shopping, users may contribute reviews that are subject to overt evaluations from other users' helpfulness ratings. Still other users may provide comments indicating agreement or disagreement with the original reviewer. This research modified congruity theory (Osgood & Tannenbaum, 1955) to predict effects on attitudes of readers who observe contributions from three potential sources of influence: review valence, other users' aggregated helpfulness rating of the review, and another user's verbal agreement or disagreement with the review. Results supported the hypothesized interaction effect among the 3 factors affecting attitudes toward a product, toward reviewers, and commenters. The findings suggest that congruity theory provides a framework for understanding effects from a juxtaposition of sources and messages within a participatory Web system.