The effects of communicating uncertainty around statistics, on public trust

Uncertainty around statistics is inevitable. However, communicators of uncertain statistics, particularly in high-stakes and potentially political circumstances, may be concerned that presenting uncertainties could undermine the perceived trustworthiness of the information or its source. In a large survey experiment, (Study 1; N = 10,519) we report that communicating uncertainty around present COVID-19 statistics in the form of a numeric range (vs. no uncertainty) may lead to slightly lower perceived trustworthiness of the number presented but has no impact on perceived trustworthiness of the source of the information. We also show that this minimal impact of numeric uncertainty on trustworthiness is also present when communicating future, projected COVID-19 statistics (Study 2; N = 2,309). Conversely, we find statements about the mere existence of uncertainty, without quantification, can reduce both perceived trustworthiness of the numbers and of their source. Our findings add to others suggesting that communicators can be transparent about statistical uncertainty without undermining their credibility as a source but should endeavour to provide a quantification, such as a numeric range, where possible.Funding was provided for these studies by the Nuffield Foundation (Grant OSP/43227). The Foundation has funded this project, but the views expressed are those of the authors and not necessarily the Foundation.. Additional funding was provided by the Winton Centre for Risk & Evidence Communication which is supported by a donation from the David & Claudia Harding Foundation