Les informations négatives sur les produits et les entreprises auxquelles les consommateurs ont accès ne sont pas toujours fiables et claires. Cette thèse étudie comment l'orientation régulatrice des consommateurs influe sur leur réaction par rapport aux informations négatives comme une fonction de l'ambiguïté des informations. Nous suggérons que lorsque les informations négatives sont ambigües, les consommateurs avec une orientation prévention, par rapport à ceux avec une orientation promotion, seront beaucoup plus influencés par les informations et susceptibles de changer en conséquence vers le bas leur attitude envers la marque. En revanche, lorsque les informations négatives sont claires, à la fois les consommateurs orientés promotion et ceux orientés prévention seront très influencés et susceptibles de revoir leur attitude à la baisse par rapport à la marque en question. De plus, nous alléguons que la diagnosticité perçue des informations exerce un rôle médiateur sur les effets proposés. Plus particulièrement, en présence des informations négatives ambiguës, l'orientation prévention (par rapport à l'orientation promotion) a tendance à amplifier la diagnosticité perçue des informations qui, en retour, accentue les effets que les informations négatives auront sur la révision de l'attitude. Quatre études expérimentales ont testé et confirmé ces hypothèses à travers trois scénarios ambigus différents : (1) quand les informations négatives proviennent d'une source dont la crédibilité est incertaine (étude 1), (2) quand la raison pour laquelle un produit défectueux est ambiguë (étude 2) et (3) quand les évaluations de produit sont très contradictoires (études 3a et 3b). / Negative information about products or companies that consumers encounter in the marketplace is not always certain and clear-cut. This dissertation explores how consumers' regulatory focus orientation affects their response to negative information as a function of information ambiguity. We propose that under the situations where ambiguity is present in the negative information, prevention-focused compared to promotion-focused consumers will be more strongly persuaded and exhibit a large downward revision of their attitude toward the brand. In contrast, under the situations where the negative information is unambiguous, both promotion and prevention-focused consumers will be strongly persuaded and revise accordingly their attitude toward the brand. Moreover, we argue that perceived diagnosticity of the information mediates the proposed effect. Specifically, in the presence of ambiguity in negative information, a prevention focus (vs. a promotion focus) leads to an inflated perceived information diagnosticity, which, in turn, accentuates the impact of negative information on judgment revision. Four experimental studies tested and confirmed these propositions in three different ambiguous scenarios: (1) when negative product information comes from a source with uncertain credibility(Study 1); (2) when the cause of a reported product failure is ambiguous(Study2), and (3) when product reviews are highly conflicting (Study 3a and Study 3b).

Part one of the thesis studies differential diagnosticity towards substantive extrinsic information available in the environment. This research tests the interaction between regulatory focus and availability of extrinsic-substantive information such as consensus information, on the range of acceptable price. Prior research on regulatory focus led us to two divergent predictions. Our findings lend support to the asymmetric-elaboration account. Under this account, only prevention-oriented consumers are likely to change their acceptable price range if combinations of favorable-and-unfavorable consensus information are available in the environment, while promotion-oriented consumers disregard such information. We find that this difference is due to the differences in the level of difficulty experienced in specifying acceptable price range across the two regulatory foci. Further, we also undertake random-parameters regression models that provide unique general findings. For example, we find that for promotion-oriented consumers it is their high-level product construal, while for prevention-oriented consumers it is their low-level product construal that influences their respective acceptable price ranges, irrespective of level of external information available. Theoretical and managerial implications are discussed.

My dissertation aims to contribute to a more comprehensive understanding of how consumers make sense of online word-of-mouth. Each essay in my dissertation probes beyond the effect of rating valence and explores the role of textual content. In the first essay, I explore negativity bias among online consumers evaluating peer information about potential sellers. I propose that both the likelihood of negativity bias and resistance to change after a trust violation will depend on the domain of information discussed in a review. Three experiments showed that negativity bias is more prominent for information regarding sellers' integrity than information regarding their competence. These findings suggest that the universality of negativity bias in a seller review setting has been exaggerated. In the second essay, I examine the impact of emotional arousal on the perceived helpfulness of text reviews. I propose an inverse U-shaped relationship by which the arousal conveyed in a text review will be associated by readers with lower perceived helpfulness only beyond an optimal level, and that the detrimental effect of arousal is present for negative reviews even when objective review content is controlled for. To test these hypotheses, two studies were conducted in the context of Apple's mobile application market. In Study 1, I collected actual review data from Apple's App Store, coded those reviews for arousal using text analysis tools, and examined the non-linear relationship between arousal and review helpfulness. In Study 2, I experimentally manipulated the emotional arousal of reviews at moderate to high levels while holding objective content constant. Results were largely consistent with the hypotheses. This essay reveals the necessity of considering emotional arousal when evaluating review helpfulness, and the results carry important practical implications. In the third essay, I explore effects of the emotions embedded in a seller review on its perceived helpfulness to readers. I propose that over and above the well-known negativity bias, the impact of discrete emotions in a review will vary, and that one source of this variance is perceptions of reviewers' cognitive effort. I focus on the roles of two distinct, negative emotions common to seller reviews: anxiety and anger. In Studies 1 and 2, experimental methods were utilized to identify and explain the differential impact of anxiety and anger in terms of perceived reviewer effort. In Study 3, actual seller reviews from Yahoo! Shopping websites were collected to examine the relationship between emotional review content and helpfulness ratings. These findings demonstrate the importance of discriminating between discrete emotions in online word-of-mouth, and they have important repercussions for consumers and online retailers.