TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE 15, 191-204 (1979) The Analysis of Expert Judgment LEONARD ADELMAN and JERYL MUMPOWER ABSTRACT Expert judgment is a necessary component oftechnology assessment. But current methods for attempting to integrate expert judgment with social value judgments in the formation of public policy are inappropriate and ineffective. This article advocates the scientific analysis of experts’ judgments. Such analysis produces quantita- tive, pictorial models of expert judgment, thereby providing an explicit and retraceable procedure for a) documenting and comparing reasons for differences in expert judgment, b) helping experts to resolve such differences, and c) conveying information to decision makers in a clear and useful fashion. The proposed approach provides an alternative to the ineffective method of public hearings and recently proposed adversarial approaches such as the “science court.” Two studies are described to illustrate this approach. Expert judgment is a necessary component of technology assessment. The frequent lack of objective data, the highly interdependent nature of system variables, and the uncertainty of future events make it necessary to rely upon expert prediction of the social effects of alternative technologies or actions. In practically all cases, scientists must go beyond the boundaries of their substantive disciplines into the realm of what Weinberg [I] has called trans-science, i.e., where science and social values interact. Often in these cases, citizen understanding of the reasons for an expert’s judgment, or the reasons for expert disagreement, is minimal. Neither citizens nor scientists can be blamed for this result. Society’s procedure, the public hearing, can, however, be sharply criticized as a means for conveying scientific information to citizens. In such hearings, citizens sit as a council of judges before which experts argue their casglike lawyers, presenting the technical pros and cons of various alternatives. The result of such focus on specific alternatives is frequent confusion of the roles and responsibilities of participants in the planning process. Citizens often become amateur experts arguing with engineers, planners, and other professionals over the techni- cal analysis of competing alternatives, instead of trying to resolve existing value and interest conflict. Similarly, experts often become social proponents of certain values or interests, instead of trying to resolve existing disagreement over technical matters. The result is that progress toward resolving conflict is often slow and laborious, since differ- ences in judgment leading to conflict are not distinguished according to whether they are differences in social values or differences in expert opinion. LEONARD ADELMAN and JERYL MUMPOWER are both Research Associates at the Center for Re- search on Judgment and Policy, Institute of Behavioral Science, University of Colorado at Boulder. During Academic Year 1978-79, Dr. Adelman was Visiting Assistant Professor of Behavioral Science at the Center for Decision Research, Graduate School of Business, University of Chicago. Dr. Mumpower is a Scientific Visitor at the National Center for Atmospheric Research, Boulder, Colorado. Reprint requests should be addressed to the Center for Research on Judgment and Policy, JBS #3, CB #485, University of Colorado at Boulder, Colorado 80309. @ Elsevier North Holland, Inc., 1979 0040-1625/79/11019114$02.25