The effects of communicating scientific uncertainty on trust and decision making in a public health context

Abstract

Large-scale societal issues such as public health crises highlight the need to communicate scientific information, which is often uncertain, accurately to the public and policy makers. The challenge is to communicate the inherent scientific uncertainty — especially about the underlying quality of the evidence — whilst supporting informed decision making. Little is known about the effects that such scientific uncertainty has on people’s judgments of the information. In three experimental studies (total N=6,489), we investigate the influence of scientific uncertainty about the quality of the evidence on people’s perceived trustworthiness of the information and decision making. We compare the provision of high, low, and ambiguous quality-of-evidence indicators against providing no such cues. Results show an asymmetric relationship: people react more strongly to cues of low quality of evidence than they do to high quality of evidence compared to no cue. While responses to a cue of high quality of evidence are not significantly different from no cue; a cue of low or uncertain quality of evidence is accompanied by lower perceived trustworthiness and lower use of the information in decision making. Cues of uncertain quality of evidence have a similar effect to those of low quality. These effects do not change with the addition of a reason for the indicated quality level. Our findings shed light on the effects of the communication of scientific uncertainty on judgment and decision making, and provide insights for evidence-based communications and informed decision making for policy makers and the public.

Meta‐informational cue inconsistency and judgment of information accuracy: Spotlight on intelligence analysis

“…For instance, we predict that evaluation of the “cannot be judged” codes to be much less susceptible to the fifty‐fifty blip response pattern if the dependent measure is not recorded on a probability scale. As Schneider et al (2022) found, pandemic‐related information whose quality was ambiguous (akin to the F/6 codes in the Admiralty Code) was rated in terms of trustworthiness as similar to information described as being of low quality. This may be due to the fact that trustworthiness ratings are unlikely to exhibit a fifty‐fifty blip.…”

Transparent communication of evidence does not undermine public trust in evidence

“…Again, there are mixed results in the literature regarding the impact of this information on perceptions of trustworthiness. Empirical evidence suggests that messages which label claims as based on “low-quality” research are rated as less trustworthy than those which reference “high-quality” research or make no mention of quality ( 26 , 27 ). Other studies have found that disclosure of evidence limitations by scientists in news or online reports can increase ( 28 , 29 ) or have no effect on perceptions of credibility or trustworthiness ( 30 , 31 ).…”

The effects of communicating uncertainty around statistics, on public trust

“…For example, claims could be accompanied by statements about ‘indirect’ uncertainty (in the sense of [9]) due to for instance a lack of data, poor quality research, disagreement among experts, or the nature of the scientific method itself [5]. The inclusion of such explanations may moderate the effects of uncertainty on perceived trustworthiness [40,74].…”

“…On the one hand, greater perceived uncertainty about future versus current events (independent of any communicated uncertainty) may lead to lower perceptions of trustworthiness or exacerbate negative effects of communicated uncertainty on trustworthiness. This view is supported by research showing that the negative effects of uncertainty information on trust in information are in part mediated by perceptions of uncertainty [6,40]. As put by the authors: ‘this suggests that the more uncertain people perceive the numbers to be, the less reliable and trustworthy they find them.’ ([6] p. 7680).…”