In the past decade researchers have begun to study how the public intuitively perceives the risks of hazardous technologies. Studies of risk perception are today widely cited by risk managers and play an active role in public discussions concerning risk policies. However, because risk perception methodology lacks a formal evaluative structure, it is often not clear how public input should be incorporated into evaluations of risky technologies or how public concerns should be weighted as part of policy decisions regarding choices among technologies. The general objective of the proposed research is to facilitate the integration of risk perception with risk evaluation approaches as part of social risk-management policies. The specific objective of the research is to explore (a) the connections between psychometric risk measures, the physical features of a technology, and sociological concerns, and (b) the legitimacy of risk-perception concerns as contributors to risk evaluations. The research will develop a better understanding of the sources and legitimacy of perceived risk by examining in-depth one key risk characteristic, dread and by testing a methodology for investigating the policy appropriateness of social concerns of risk.