Evidence of what worked, at some point, in some place

A major highlight at this year’s annual conference of the German Evaluation Society (DeGEval) was Prof. Gert Biesta’s keynote speech on research as a provider of evidence for policy. “Evidence-based” is a buzzword in development (as well as other disciplines, such as education); bilateral and multilateral donors have mobilised considerable funding to “building an evidence base”. The basic idea is that interventions should be based on the best possible evidence of what works. In his speech, Biesta unravelled the meanings of “intervention”, “evidence” and “what works” to raise fundamental questions: What role should evidence play in policy making? What kind of evidence are we talking about, anyway, and can it replace professional judgement and wider democratic deliberation?