Despite a remarkable increase over the past decade in the use of stakeholder groups as part of efforts to manage environmental and health risks, little attention has been given to research that will improve group decision processes. This award addresses this gap through two interrelated research efforts. First, investigators will examine the theory of group decision processes, in order to assist stakeholders participating in risk or environmental management controversies to provide useful input to the design of actions and policies. Second, they will test the effectiveness of these recommendations by establishing criteria for measurement of a `better` decision and designing experiments to test and compare various approaches to group decisionmaking. The questions to be addressed by these two facets of the research are both fundamental and challenging: What is citizen involvement in risk management intended to achieve? How can we measure its success? How much involvement is enough? How does a policy maker know that stakeholder perspectives have been incorporated faithfully? How can the insights of stakeholders best be presented to decision makers? Among the benefits of this research will be the design of better techniques for helping health and environmental risk managers to incorporate stakeholder objectives, as well as a better dialogue across practitioners and policy makers regarding the steps to be used in facilitating and assessing public involvement processes.