New Nuffield-funded research has found that uncertainty around key facts and figures can be communicated in a way that maintains public trust in information and its source, even on contentious issues such as immigration and climate change.
This finding is particularly important as the numbers that drive newspaper headlines – those on Covid-19 infections, for example – often contain significant levels of uncertainty: assumptions, limitations and extrapolations.
Experts and journalists have long assumed that revealing the ‘noise’ inherent in data confuses audiences and undermines trust. The research team at the University of Cambridge hope these findings will encourage scientists and media to be bolder in reporting statistical uncertainties.
“Estimated numbers with major uncertainties get reported as absolutes. This can affect how the public views risk and human expertise, and it may produce negative sentiment if people end up feeling misled,” said Dr Anne Marthe van der Bles, who led the new study while at Cambridge’s Winton Centre for Risk and Evidence Communication.
The team of psychologists and mathematicians conducted five experiments involving a total of 5,780 participants, including a unique field experiment hosted by BBC News online, which displayed the uncertainty around a headline figure in different ways.
The researchers got the best results when a figure was flagged as an estimate, and accompanied by the numerical range from which it had been derived, for example: “…the unemployment rate rose to an estimated 3.9% (between 3.7%–4.1%)”.
This format saw a marked increase in the feeling and understanding that the data held uncertainty, but little to no negative effect on levels of trust in the data itself, those who provided it (e.g. civil servants) or those reporting it (e.g. journalists).
“We hope these results help to reassure all communicators of facts and science that they can be more open and transparent about the limits of human knowledge,” said co-author Prof Sir David Spiegelhalter, Chair of the Winton Centre at the University of Cambridge.
Catherine Dennison, Welfare Programme Head at the Nuffield Foundation, said: “We are committed to building trust in evidence at a time when it is frequently called into question. This study provides helpful guidance on ensuring informative statistics are credibly communicated to the public.”
The findings are published today in the journal Proceedings of the National Academy of Sciences. The team worked with the BBC to conduct a field experiment in October 2019, when figures were released about the UK labour market.
Disinformation often appears definitive, and fake news plays on a sense of certainty. One way to help people navigate today’s post-truth news environment is by being honest about what we don’t know, such as the exact number of confirmed coronavirus cases in the UK. Our work suggests people can handle the truth.Sander van der Linden, co-author and Director of the Cambridge Social Decision-Making Lab
