I don’t know what to believe

This booklet explains how scientists present and judge research using the peer review process, and how the public can make sense of science stories.

Published: 2005; updated 2017
All our guides are date stamped and reflect the scientific findings and knowledge available at the time of publication.


Did you Know?

There are around 28,000 scholarly and scientific journals that use the peer review system. A high proportion of these are scientific, technical or medical journals, publishing over 1 million research papers each year.


Every day we are bombarded with information about science from newspapers, radio and television programmes and the internet. Making sense of it all can be very difficult. What should be taken seriously? Which are ‘scares’? Sometimes scientists are reported as saying conflicting things. How do we know what to believe?


This guide has been produced and distributed with sponsorship and help from: Elsevier, Wiley, Royal Pharmaceutical Society, MRC, Royal Society of Biology, Blackwell Publishing and Taylor & Francis Group.

Sense about Science is grateful for the input of the sponsors, the many organisations (in particular Cancer Research UK, Asthma UK, The Migraine Trust and Action Medical Research), parliamentarians, government officials, educational organisations, teachers, school students, doctors, pharmacists, science bodies and the many others, who kindly contributed their time and ideas.

I don't know what to believe partner logos: Elsevier, MRC, Royal Pharmaceutical Society, Royal Society of Biology, Taylor & Francis, Wiley

What is the problem this guide is addressing?

There is a system used by scientists to decide which research results should be published in a scientific journal. This system, called peer review, subjects scientific research papers to independent scrutiny by other qualified scientific experts (peers) before they are made public. Peer review can help you make sense of science stories as it tells you that the research has passed the scrutiny of other scientists and is considered valid, significant and original.

Peer review means that statements made by scientists in scientific journals are critically different from other kinds of statements or claims, such as those made by politicians, newspaper columnists or campaign groups. Science is therefore more than just another opinion.


More than 500,000 copies of the guide have been requested by the NHS, patient helplines, schools, Government, universities and others. Tracey Brown wrote about the launch for The Scientist and was quoted in the Times Higher Education Supplement saying groups were “very fired up” about encouraging non-scientists to talk about the status of research. The guide was brought to the attention of MPs by House Magazine in an article expressing the importance of parliamentarians understanding peer review.


This guide has been translated into Mandarin. We also created a version for a US audience.

I don’t know what to believe (China)
Translated by Yue Yuan, Editor, San Lian Life Weekly.
Published: May 2013

I don’t know what to believe (USA)
Published: February 2013


Published: 8 November 2016