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

Journal of Computer-Mediated Communication Online Reviews, Helpfulness Ratings, and Consumer Attitudes: An Extension of Congruity Theory to Multiple Sources in Web 2.0 Joseph B. Walther Department of Communication, Michigan State University, USA and Department of Telecommunication, Information Studies & Media, Michigan State University, USA, Yuhua (Jake) Liang Department of Communication, Michigan State University, USA Tina Ganster Department of Social Psychology: Media and Communication, University of Duisburg-Essen, Germany Donghee Yvette Wohn Department of Telecommunication, Information Studies & Media, Michigan State University, USA Josh Emington Department of Communication, Michigan State University, USA 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. Key words: Congruity theory, Online Reviews, Helpfulness Ratings, User-generated content doi:10.1111/j.1083-6101.2012.01595.x Participatory websites provide complex communication systems that confront readers with information from a variety of sources in a variety of forms. Web 2.0 sites that host online shopping are an increasingly important part of overall consumerism; the percentage of adult online shoppers in the US tripled from 22% in 2000 to 66% in 2008 (Horrigan, 2008). Accompanying the rise of online shopping is consumers’ reliance on user-generated reviews and ratings that appear on these sites (Willemsen, Neijens, Bronner, & de Ridder, 2011). Journal of Computer-Mediated Communication 18 (2012) 97–112 © 2012 International Communication Association 97 Multiple Sources of Influence and Web 2.0 Systems Consumers are often exposed to multiple user-generated sources and messages when shopping for products online. A typical site may offer at least three different sources of influence. First, user-generated reviews present experiences and opinions written by other consumers. The positivity or negativity of a review’s content is the valence of the recommendation (see Lee, Rodgers, & Kim, 2009). Second, other users evaluate these online reviews and generate helpfulness ratings (Otterbacher, 2009; Willemsen et al., 2011), which the site compiles and displays as aggregate ratings for yet other readers to see. These displays are often presented as a proportion of users who found others’ reviews helpful (e.g., ‘‘95 out 100 people found this review helpful’’). Third, online review sites solicit comments from other readers, whose verbal statements may connote agreement or disagreement. Most comments reflect personal experiences or evaluations that support or rebut the original review. Examples of agreeing comments may include ‘‘yes, that’s what happened!’’ or ‘‘I also think this product is great!’’ Disagreeing comments may be ‘‘that’s not what happened!’’ or ‘‘I disagree that this product worked well!’’ Predicting the relative effects of these multiple sources of social influence presents conceptual challenges. Walther et al. (2010a) suggest approaching the challenge by classifying sources in terms of their relationship to the receiver, and on that basis, applying traditional theories to help explain their likely effects. Congruity theory offers one such possibility. Congruity Theory Numerous theories explain the influence of an individual source’s recommendation (or rejection) of a specific product or object on a receiver’s attitude. Some of these theories deal with sequential messages, but most of these theories focus on sequential messages from a single source. Few theories explain how receivers deal with two sequential messages from two independent sources (cf., McGuire, 1964). 98 Journal of Computer-Mediated Communication 18 (2012) 97–112 © 2012 International Communication Association Research has begun to investigate the influence of user-generated reviews on other consumers’ purchase decisions. Consumers apparently regard user-generated reviews as more trustworthy than traditional advertising information (Huang, Chou, & Lan, 2007). Influential properties of these reviews include the positive (vs. negative) user-generated descriptions of products (Chevalier & Mayslin, 2006; Dellarocas, Zhang, & Awad, 2005) and the sheer volume of product reviews (Duan, Gu, & Whinston, 2005; Liu, 2006). Research also shows that source characteristics associated with the author of a product review shape consumers’ perceptions of products (Forman, Ghose, & Wiesenfeld, 2006). A variety of message features also affect responses (Dellarocas et al., 2005), such as valence, argument density, argument diversity, and the writer’s expertise claims (Willemsen et al., 2011). Despite the growing knowledge about the effects of various components in participatory review systems, an important characteristic of these sites has eluded investigation. Most research concerning user-generated product evaluations examined one facet of these systems to the exclusion of others. However, like many other participatory websites, review sites offer a juxtaposition of multiple sources of influence (see Walther et al., 2010a), such as the users’ reviews, aggregated user representations reflecting others’ ratings of the reviews, and individual comments about reviews, provided by different individuals and groups. Decoding the interplay of these various elements when they appear simultaneously and how they affect readers’ responses comprises one of the major challenges in understanding Web 2.0 as a communication system. The present research brings theory to bear that offers specific predictions for the influence of the combination of these types of sources and messages on consumers. An original experiment tested derived predictions using mock-up online product pages. Associative and Dissociative Statements When a source and an object initially differ from one another in terms of a receiver’s liking for each of these entities, and a source expresses an association between the source and object, the discrepancy creates degrees of pressure toward reconciliation, or congruity, among the source and the object. The receiver changes attitudes about these entities so that the evaluation of each becomes more similar. If a liked source makes an associa (...truncated)