Randomised control trials (RCTs) are a type of trial and evaluation. They began in medical and pharmacological testing and are now increasingly used in international development, business, and policy to identify which interventions and approaches are most effective. RCTs work by introducing a randomly assigned control group. This allows people to compare the impact of the intervention against what would have happened if nothing had been changed.
RCTs have been used in the UK particularly by the behavioural insights team (initially part of the Cabinet Office, now a social purpose company part-owned by government, Nesta, and the employees).
Start using RCTs
When planning evaluations and trialling, ask your analysis and social research teams in your department for advice to make sure your trial produces rigorous findings. RCTs can be relatively simple if they are carried out online, eg by testing responses to different emails. You should start by reading the behavioural insights team’s helpful guide on how to carry out RCTs.
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