This short document aims to provide a summary of the main issues that people engaged in developing drug policy, or in commissioning evaluations of drug policy, strategies and interventions, need to consider. There are many sources of more detailed information and guidance on conducting evaluations. This guide seeks not to duplicate or replace them but instead to act as an introduction, providing links to the wider literature and presenting the key issues for those managing rather than undertaking drug policy evaluations. Further reading and sources of more detailed information are provided at the end of this guide. There is also no single correct way to undertake an evaluation, and the choice of approach depends on many factors, including timing, objectives and the availability of resources. This publication is designed to assist people in choosing the best approach to suit their circumstances and to maximise the value of any evaluation.

There is a lot written about evaluation and sometimes the same terms are used to mean different things, so before starting it is important to clarify the definitions and concepts that the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) uses in this guide. The box below provides the definitions that we use in this guide for certain core concepts.