Communicating Forecast Uncertainty for Lower-Numeracy Populations

Numeracy, or the ability to understand and work with numbers, may be an essential consideration when deciding how best to communicate forecast uncertainty to the public. In this presentation, the author will suggest a design standard for emerging weather technologies that considers the needs of the lesser-numerate, a population that has already proven more vulnerable in contexts such as financial decision-making. The presentation will highlight results from a warning decision study of over 5000 members of the US public where respondents were provided with deterministic warning information or probabilistic information and then asked to make a series of protective action decisions. In general, respondents were able to make better decisions when provided with probabilistic information, but lesser-numerate participants fared worse than their more numerate counterparts. The presentation will explore the potential for additional cues, such as verbal guidance or intuitive color scales, to improve decision-making for this population. Implications of the results for operational practice will be discussed.