Making Sense of Uncertainty

Why uncertainty is part of science.
In public discussion, scientific uncertainty is often presented as a deficiency of research. In reality, it’s an essential part of scientific research.

Published: 27 June 2013
All our guides are date stamped and reflect the scientific findings and knowledge available at the time of publication.

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The term ‘uncertainty’ is unquestionably fraught with misinterpretation – especially for non-scientists. I’d prefer the phrase ‘how confident am I?”, the reciprocal of uncertainty.

Prof Sir Michael Rawlins

Chair, National Institute of Clinical Excellence

Did you Know?

Decision-makers generally look for a higher level of certainty for an operational decision (such as introducing body scanners in airports) than for a decision based on broader ideology or politics (such as reducing crime rates).


Scientific uncertainty is prominent in research that has big implications for our society: could the Arctic be ice-free in summer by 2080? Will a new cancer drug be worth its side effects? Is this strain of ‘flu going to be a dangerous epidemic? This guide has brought together specialists in many areas – climate science, clinical research, natural hazard prediction, public health, biostatistics and epidemiology. We asked them for the reasons why they are not automatically so troubled by the presence of uncertainty in the most heated debates.


This guide was produced in collaboration with BBSRC, the John Innes Centre, the Natural Environment Research Council, the University of Reading and the Walker Institute. Reprinted in 2014 with support from All Souls College, University of Oxford, the Winton Programme for the Public Understanding of Risk and the School of GeoSciences, University of Edinburgh.

What is the problem this guide is addressing?

In public discussion, scientific uncertainty is presented as a deficiency of research. We want (even expect) certainty – safety, effective public policies, useful public expenditure. Uncertainty is seen as worrying, and even a reason to be cynical about scientific research – particularly on subjects such as climate science, the threat of disease or the prediction of natural disasters. In some discussions, uncertainty is taken by commentators to mean that anything could be true, including things that are highly unlikely or discredited, or that nothing is known.

We have looked at what uncertainty means and doesn’t mean in science, how it is measured, when it can’t be measured and how that might change through research into the big questions. Above all we asked how other people can grapple constructively with advances in knowledge and changes in thinking, instead of despairing at ‘those uncertain scientists’.


The launch of Making Sense of Uncertainty sparked a flurry of activity on social media. BBC Radio 4 talked about the guide in Material World. Publishers and universities such as Wiley, the University of Manchester and London School of Economics and Political Science wrote articles and NERC blogged about the guide. This continues to be one of our most popular guides, and we often write about this subject.

Listen to Tracey Brown’s Guardian podcast on the nature of scientific uncertainty. (2 Oct 2015)