There are increasing calls for policy and practice to be "evidence informed." At surface value, there may appear much to commend such an approach. However, it is important to understand that "evidence" and "knowledge" are being mobilised in very particular ways. The danger is that rather than promote a rich and lively debate about what counts as evidence, and how it can help educators, the reality is the development of a narrow "what works" agenda which in turn imposes a "one best way" approach to pedagogical practice.