Virtuous opinion change in structured groups

Bolger, Fergus; Rowe, Gene; Hamlin, Ian; Belton, Ian; Crawford, Megan; Sissons, Aileen; Taylor Browne Lūka, Courtney; Vasilichi, Alexandrina; Wright, George

Abstract

Although the individual has been the focus of most research into judgment and decision-making (JDM), important decisions in the real world are often made collectively rather than individually, a tendency that has increased in recent times with the opportunities for easy information exchange through the Internet. From this perspective, JDM research that factors in this social context has increased generalizability and mundane realism relative to that which ignores it. We delineate a problem-space for research within which we locate protocols that are used to study or support collective JDM, identify a common research question posed by all of these protocols—‘What are the factors leading to opinion change for the better (‘virtuous opinion change’) in individual JDM agents?’—and propose a modeling approach and research paradigm using structured groups (i.e., groups with some constraints on their interaction), for answering this question. This paradigm, based on that used in studies of judge-adviser systems, avoids the need for real interacting groups and their attendant logistical problems, lack of power, and poor experimental control. We report an experiment using our paradigm on the effects of group size and opinion diversity on judgmental forecasting performance to illustrate our approach. The study found a U-shaped effect of group size on the probability of opinion change, but no effect on the amount of virtuous opinion change. Implications of our approach for development of more externally valid empirical studies and theories of JDM, and for the design of structured-group techniques to support collective JDM, are discussed.

• Journal Article Type: Article
• Acceptance Date: Jun 20, 2023
• Online Publication Date: Aug 3, 2023
• Publication Date: 2023
• Deposit Date: Aug 6, 2023
• Publicly Available Date: Aug 7, 2023
• Journal: Judgment and Decision Making
• Print ISSN: 1930-2975
• Publisher: Society for Judgment and Decision Making
• Peer Reviewed: Peer Reviewed
• Volume: 18
• Article Number: e25
• DOI: https://doi.org/10.1017/jdm.2023.22
• Keywords: group judgment, judge-adviser systems, Delphi, judgmental forecasting, crowdsourcing