Effective risk management often requires effective risk communication. Risk communicators cannot afford to assume that those who receive their communication do so with a tabula rasa. Readers use their prior knowledge to organize and understand new information. Both the contents and organization of readers' prior knowledge affect how they interpret new information. Therefore risk communication should be more effective if it (1) addresses prior misconceptions, and (2) takes into account the readers' goals, prior knowledge, and cognitive limitations in processing new information. In the context of risk communication, these propositions have not been adequately evaluated. This project attempts to fill this gap. The first study examines several designs for dispelling misconceptions about global climate change and 60 Hertz electric and magnetic fields. The second study examines the influence of text structure and text comprehension aids on risk communication effectiveness. The third study integrates the results of the first two into two complete risk communications that differ structurally. Multiple measures are proposed to evaluate risk communication effectiveness in all studies, including performance on recall, recognition, and problem-solving tasks. The project will produce empirically tested documents and evaluation instruments as well as practical guidelines for risk communicators. Contributions to risk perception, risk communication and risk communication evaluation research are anticipated.
