Making Sense of Uncertainty

28 Jun 2013

Think uncertainty is a bad thing? It’s actually a mark of sound science.

Scientists and research institutes are challenging the idea that uncertainty in research is a reason for people to worry about the reliability of findings.

Researchers in climate science, disease modelling, epidemiology, weather forecasting and natural hazard prediction say that we should be relieved when scientists describe the uncertainties in their work. It doesn’t necessarily mean that we cannot make decisions – we might well have ‘operational knowledge’ – but it does mean that there is greater confidence about what is known and unknown.

Launching a guide to Making Sense of Uncertainty at the World Conference of Science Journalists today, researchers working in some of the most significant, cutting edge fields say that if policy makers and the public are discouraged by the existence of uncertainty, we miss out on important discussions about the development of new drugs, taking action to mitigate the impact of natural hazards, how to respond to the changing climate and to pandemic threats.

Interrogated with the question ‘But are you certain?’, they say, they have ended up sounding defensive or as though their results are not meaningful. Instead we need to embrace uncertainty, especially when trying to understand more about complex systems, and ask about operational knowledge: ‘What do we need to know to make a decision? And do we know it?’

In Making Sense of Uncertainty they review the current discussion and discuss: 
• The way scientists use uncertainty to express how confident they are about results
• That uncertainty can be abused to undermine evidence or to suggest anything could be true: from alternative cancer treatments to anthropogenic CO2 not changing the atmosphere.
• Why uncertainty is not a barrier to taking action – decision makers usually 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).

Tracey Brown, Managing Director, Sense About Science: “Scientific research doesn’t just produce information – about earthquake frequency or the causes of cancer - it estimates how much of the picture we have by trying to measure the uncertainty in that information. However, this does not mean that we are waiting for the day of certainty to arrive! It is especially important to recognise that in discussions where we have decisions to make, about whether to spend more on buildings that withstand earthquakes and whether to stockpile a vaccine. Instead, ‘do we have operational knowledge?’ is one of the most useful questions anyone can ask.”

Dr Frank de Vocht, Lecturer in Occupational and Environmental Health in the Institute of Population Health, at The University of Manchester, said: “Uncertainty is the most important factor that drives scientific development. It is important to understand what it means for policy makers, researchers, journalists and the public because of its potential to be misused for political, economic or ideological gain.”
David Stainforth, Senior Research Fellow, Grantham Research Institute, London School of Economics, said: “Uncertainty is simply part of our understanding. Sometimes the details matters, sometimes they don’t, but uncertainty is not a barrier to taking good decisions. Nor is it unfamiliar. We all take decisions under uncertainty every day.”
Angela Mclean, Professor of Mathematical Biology, University of Oxford, said: “If you can quantify the uncertainty around a statement then you have gone a long way towards understanding what is going on.”

To view the guide, visit:



Notes for editors

For details of The University of Manchester's involvement, please contact:

Alison Barbuti | Media Relations Officer | Faculty of Medical and Human Sciences |The University of Manchester
Tel. +44 (0)161 275 8383 | Mobile 07887 561 318 |Email:

For more information or interviews contact Tabitha Innocent (in Helsinki) on or +44 (0) 7949610702 or Sense About Science on +44 (0)20 7490 9590 or

For hard copies of the guide email Tabitha Innocent on

Notes to editors

1 There is a press briefing on this guide at the World Conference of Science Journalists 2013 in Helsinki on 27th June 12.30 EEST in the University of Helsinki, Main Building Fabianinkatu 33, 2nd floor, Consistory Hall

2. The guide will be launched to the public at a panel session of the World Conference of Science Journalists 2013 in Helsinki on 27th June at 14:50 – 15:30 EEST in the University of Helsinki, Main Building Fabianinkatu 33, Auditorium XIV.
Speakers at the panel session:
(Chair) Dr Leonor Sierra, science writer, University of Rochester
James Painter, Head of Journalism Fellowship Programme, Reuters Institute for the Study of Journalism
Dr Tabitha Innocent, Scientific Liaison, Sense About Science
Fabio Turone, Science journalist based in Milan, President of Science Writers in Italy, board member of EUSJA
For more information about the panel session see

3. The publication of Making Sense of Uncertainty was made possible by our partners Biotechnology and Biological Sciences Research Council; Natural Environment Research Council; Walker Institute for Climate System Research, University of Reading; University of Reading; John Innes Centre.

4. Sense About Science is a UK charity that equips people to make sense of evidence and campaigns for sound science and evidence in public life.