Different Formats for the Communication of Risks: Verbal, Numerical, and Graphical Formats

Abstract

AbstractDifferent formats are available for the communication of the quantitative aspect of risks: verbal terms, numbers, and graphical representations. Verbal terms, such as alarge chance, are often used but may lead to confusion, because the exact meaning is not clear. The majority of people therefore, prefer to receive risk information in numerical terms. These numerical formats have the drawback, however, that people often find them difficult to comprehend. When using numerical risk formats two generic characteristics are important for optimizing risk perceptions and decision making. First, more concrete formats seem to evoke more meaningful risk images, which improve risk perception. Therefore, it seems advisable to use a frequency format and small numbers, for example, lower denominators (“1 inX”). Second, in more complex situations, it is particularly important to minimize the complexity of risk information and to present risks so that errors are prevented. This means, for instance, that the risks that are most relevant for the specific decision need to be made explicit and that computations should be avoided. Graphical formats may also be used to communicate risks. There is limited evidence that suggests that graphical formats substantially improve understanding and aid decision making. However, graphical displays can look appealing and could be effective in drawing a person's attention, which may lead to increased awareness of the risk.