This award funds research to develop improved methods for using risk comparisons in risk communications. Risk comparisons, which compare the estimates of risk from one source to those from another source, are intuitively appealing as a means for aiding the communication and understanding of risk estimates. However, past applications have been criticized because they failed to account for qualitative differences between risks (e.g., discrete vs. continuous risk sources) and because they ignored important attributes that affect risk perception (e.g., voluntary vs. involuntary exposure). The proposed research plan includes the development of a conceptual model for guiding the identification and evaluation of risk comparison methods. The conceptual model will summarize available information regarding the communication process and include explicit evaluation criteria. Using the example of health risks from electromagnetic fields, a set of risk comparisons will be developed for illuminating specific aspects of risk. Focus groups, which involve in-depth interviews with selected participant groups, will be conducted to test the effectiveness of the methods and to collect additional information concerning (a) how characteristics of the affected population should influence the selection of a risk comparison method, (b) what characteristics of the risk source typically determine the choice of reference risks, and (c) how uncertainties in risk estimates should be presented. On the basis of these results, an implementation strategy and evaluation criteria for the use of risk comparisons will be recommended. This information will be of use to risk analysts, decision makers, and others who must communicate risk information.
