Organizational Behavior and Human Decision Processes Vol. 80, No. 3, December, pp. 228–251, 1999 Article ID obhd.1999.2859, available online at http://www.idealibrary.com on Comparison Opportunity and Judgment Revision A. V. Muthukrishnan Hong Kong University of Science and Technology, Kowloon, Hong Kong Michel Tuan Pham Columbia University and Amitabh Mungale ´ Rutgers University Prior evaluations are frequently challenged and need to be revised. We propose that an important determinant of such revi- sions is the degree to which the challenge provides an opportu- nity to compare the target against a competitor. Whenever a challenge offers an opportunity, the information contained in the challene will carry a disproportionate weight in the revised judgments. We call this proposition the comparison–revision hypothesis. In Experiments 1–3, we manipulated comparison opportunity by varying the format of the challenge and examined the weights assigned to different inputs in the revised judgments. The results indicate that prior information about the target receives a greater weight under a noncomparative challenge (which provides information only about the target) than under a comparative challenge (which compares the target with a com- petitor). In contrast, information presented in the challenge The authors thank Joe Alba, Gerry Gorn, Madan Pilutla, Lydia Price, Priya Raghubir, S. Ramas- wami, Bob Wyer, and participants in seminars at Columbia University, INSEAD, HKUST, and Stanford University for their comments and suggestions. We also thank the reviewers and the associate editor for their comments. The research was funded by a competitive earmarked research grant (CERG) from the Hong Kong Research Grant Council. Address correspondence and reprint requests to A. V. Muthukrishnan, Assistant Professor, Department of Marketing, Hong Kong Universityof Science & Technology, Clearwater Bay, Kow- loon, Hong Kong (E-mail: mkmuthu@uxmail.ust.hk.), or to Michel Tuan Pham, Associate Professor, Graduate School of Business, Columbia University, Uris Hall 515, 3022 Broadway, New York, NY 10027 (E-mail: tdp4@columbia.edu). 228 0749-5978/99 $30.00 Copyright  1999 by Academic Press All rights of reproduction in any form reserved.