The degree of uncertainty and ambiguity that exists in the minds of people about the risks they may face varies according to the methods used in communicating those risks and is of particular importance to their response. This project explores how people respond to ambiguous information about environmental risks, how EPA should best communicate those risks, and how individuals respond to different forms of information about the environmental risks they may face. Different ways of communicating risks will be used. The survey will be computerized and analyzed using appropriate econometric techniques. The study includes identifying and understanding the conditions under which people express aversion to uncertainty or ambiguity about environmental risks. Researchers will explore how the degree of ambiguous belief varies with the magnitude and range of risk and its degree of asymmetric distribution. The degree of risk experiences in decision making, the competence that decision makers possess and the control they can exert over their own level of exposure will also be taken in consideration.