This volume is an outgrowth of a NATO Advanced Research Workshop on "Expert Judgment and Expert Systems," held in Porto, Portugal, August 1986. Support for the Workshop was provided by the NATO Division of Scientific Affairs, the U.S. Army Research Institute, and the U.S. National Science Foundation. The Workshop brought together researchers from the fields of psychology, decision analysis, and artificial intelligence. The purposes were to assess similarities, differences, and complementarities among the three approaches to the study of expert judgment; to evaluate their relative strengths and weaknesses; and to propose profitable linkages between them. Each of the papers in the present volume is directed toward one or more of those goals. We wish to express our appreciation and thanks to the following persons for their support and assistance: John Adams, Vincent T. Covello, Luis da Cunha, Claire Jeseo, B. Michael Kantrowitz, Margaret Lally, Judith Orasanu, R. M. Rodrigues, and Sandor P. Schuman.

This volume is the outcome of a recent NATO Advanced Study Institute (ASI) on "Technology Assessment. Environmental Impact Assessment. and Risk Analysis: Contributions from the Psychological and Decision Sciences." The Institute was held in Les Arcs. France and functioned as a high level teaching activity during which scientific research results were presented in detail by eminent lecturers. Support for the Institute was provided by grants from the NATO Division of Scientific Affairs. the u.S. Office of Naval Research. and the Russell Sage Foundation. The Institute covered several areas of research. including quantitative studies on decision and judgmental processes. studies on human intellectual limitations. studies on risk attitudes and perceptions. studies on factors contributing to conflicts and disputes about hazardous technologies and activities. studies on factors influencing forecasts and judgments by experts. studies on public preferences for decisionmaking processes. studies on public responses to technological hazards. and case studies applying principles and methods from the psychological and decision sciences in specific settings.

Planning for the management of nuclear wastes, whatever their level of radioactivity, is one of the most important environmental problems for all societies that produce utility, industrial, medical, or other radioactive waste products. Attempts to site low-level radioactive waste disposal facilities in Western industrial societies, however, have repeatedly engendered conflicts between governments, encountered vehement opposition on the part of local citizen groups, and given rise to overt hostilities among involved parties. "LLRW Disposal Facility Siting" is the result of a study designed to learn more about the causes underlying failed and successful efforts to site LLRW disposal facilities. The study is based on case histories of LLRW disposal facility siting processes in six countries. Siting processes in five states within the United States and in five additional countries are analyzed using information obtained from public documents and supplemented by interviews with key participants. The selected states and countries are major generators of LLRW and each has made efforts to establish LLRW disposal facilities between 1984 and 1994. They vary widely in the approaches they have adopted to LLRW management, the institutional structures developed for managing the siting process, the means used to involve stakeholders and technical experts in the facility siting process and the amount and type of data used in making decisions. The analysis of these case histories provides general lessons about the advantages, disadvantages, strengths, and weaknesses of the various approaches that have been attempted or implemented. The text provides data for academics and researchers working in the area of environmental management.