David Spiegelhalter is Winton Professor for the Public Understanding of Risk, and Professor of Biostatistics, at the University of Cambridge. His background is in medical statistics, particularly the use of Bayesian methods in clinical trials, health technology assessment and drug safety. In his post he leads a small team (UnderstandingUncertainty.org) that attempts to improve the way in which the quantitative aspects of risk and uncertainty are discussed in society. He works closely with the Millennium Mathematics Project in Cambridge in trying to develop an exciting treatment of probability and risk for mathematics education. He gives many presentations to schools and others, advises organisations and government agencies on risk communication, and is a regular commentator on current risk issues. He presented the BBC4 documentaries ‘Tails you Win: the Science of Chance” and “Climate Change by Numbers”. He is a Fellow of Churchill College Cambridge, an Honorary Fellow of the Institute for Risk Management, an Honorary Fellow of the Royal College of Physicians, and was elected Fellow of the Royal Society in 2005. He as awarded an OBE in 2006 and knighted in 2014, both for services to medical statistics.