Barak Ariel is a Professor of Experimental Criminology at the University of Cambridge and an Associate Professor at the Hebrew University of Jerusalem. His areas of research include experimental designs, spatial analyses of crime, and policing. Matthew Bland is an Associate Professor in Evidence-based policing at the University of Cambridge. Dr Bland is the former head of analysis in two police forces in England and Wales. His research interest is domestic abuse, and specifically analysing police data. Alex is Chief Scientist and Director of Research and Evaluation at the Behavioural Insights Team (AKA ′the nudge unit′). Before joining BIT, Alex was at RAND Europe for 5.5 years, and spent three years teaching research design/quantitative methods at the University of Cambridge. Prior to Cambridge, he worked at the Centre for Criminology, University of Oxford and has a D.Phil. in sociology, also from Oxford. His interests cover evaluation of public policy, randomised trials, and research design.