The evidence movement and the idea of systematic reviews, defined as summaries of the results of already existing evaluation and research projects, have gained considerable support in recent years as many international as well as national evidence-producing organizations have been established. This article analyses how the idea is practised in the areas of health, social welfare and education and shows that evidence-producing organizations work differently. Some subscribe to the hierarchy of evidence, others to a typology of evidence. The consequences of these variations are discussed.