Not as gloomy as we thought: reassessing how the public understands probability of precipitation forecasts

Abstract

Prior research asking people to interpret probability of precipitation (PoP) forecasts showed that many of them wrongfully believe that PoP forecasts are derived from a percentage of time, a percentage of a region or the strength of agreement among forecasters. We posit that the wording of PoP interpretation tasks matters, because it is associated with different metacognitive feelings used as cues in situations of uncertainty. We hypothesised that the fluency of the correct PoP interpretation is lower than the fluency of the incorrect interpretations and will, in turn, increase preference for the incorrect interpretations. We assessed the role of fluency in correctness perception (Study 1) and reassessed PoP interpretations with a more fluent correct interpretation (Study 2). Fluency perception was positively related with perception of correctness. Furthermore, participants selected the correct fluent interpretation more often than the correct disfluent one. We have drawn a more optimistic picture of people's PoP forecasts understanding than that shown before and have discussed the methodological and applied implications.

Perceptions, Uses, and Interpretations of Uncertainty in Current Weather Forecasts by Spanish Undergraduate Students

“…However, it seems that the probability terminology definition of PoP forecasts has not been consistently and adequately explained, in general, to Spanish students participating in the current study. In this regard, other researchers emphasize the need of promoting the use of probabilistic weather forecasts (see, e.g., Fundel et al 2019;Fleischhut et al 2020) by means of a more fluent and simple view on PoP forecasts interpretation that would help weather forecast users to believe in the quality of the interpretation and its utility (Juanchich and Sirota 2019). In this regard, Handmer and Proudley (2007) showed that the participants in their study generally understood the basic probability concept used in weather forecasts.…”

“…They found that uncertainty was only expressed for probability of precipitation (PoP) in their study sample, and it was generally conveyed in a percentage format. Additionally, although the use of probabilistic weather forecasts has been widely promoted (see, e.g., National Research Council 2006;Sivle 2016;Fundel et al 2019;Fleischhut et al 2020), Juanchich and Sirota (2019), based on informal observations, also highlighted that it is currently rare to see probabilistic forecasts on British or American TV channels, or contain at best limited information about uncertainty (Morss et al 2008). This issue could produce false certainty in forecasts in the target audience of these weather products, not admitting that forecasts may sometimes fail.…”

“…Different studies (Gigerenzer et al 2005;Morss et al 2008;Joslyn et al 2009;Morss et al 2010;O'Hanrahan and Sweeney 2013;Peachey et al 2013;Abraham et al 2015;Zabini et al 2015;Stewart et al 2016) pointed out that end users are unable to state correctly the interpretation of the PoP forecasts. However, other researchers presented a more positive view on PoP forecasts interpretation (see, e.g., Konold 1989;Roulston et al 2006;Handmer and Proudley 2007;Roulston and Kaplan 2009;Stephens et al 2019;Juanchich and Sirota 2019). They showed that a wide range of factors impact how people understand probabilities, but weather forecasters should provide the public a fluent definition of PoP and emphasize the fact that precipitation is not certain.…”

“…Therefore, this line of research has been promoted in the last years, considering different geographical locations as well as distinct target audiences. Morss et al (2008), Lazo et al (2009), Morss et al (2010), Joslyn and Savelli (2010), Stewart et al (2016), and Juanchich and Sirota (2019) applied their research in the United States. Joslyn and Savelli (2010) reported their results based on university undergraduates' responses in the Pacific Northwest region of the United States.…”

“…Peachey et al (2013) and Abraham et al (2015) developed their studies with university students and the general public, respectively, in the United Kingdom. Juanchich and Sirota (2019) conducted research with regard to the interpretation of probabilities of precipitation with participants from the United States and the United Kingdom. O'Hanrahan and Sweeney (2013) distributed a survey to weather enthusiasts in the Republic of Ireland in order to evaluate the level of understanding of probabilistic forecasting and their willingness to use these types of forecasts.…”