The twenty-first century experimenting society: the four waves of the evidence revolution

Abstract This paper presents a personal perspective–drawing especially on the author’s experience in international development—of the evidence revolution, which has unfolded in fours waves over the last 30 years: (1) the results agenda as part of New Public Management in the 1990s, (2) the rise of impact evaluations, notably randomized controlled trials (RCTs) since the early 2000s, (3) increased production of systematic reviews over the last ten years, and (4) moves to institutionalize the use of evidence through the emergence of knowledge brokering agencies, most notably the What Works movement in the United States and the United Kingdom. A fifth wave may come from the potential from AI, machine learning and Big Data. Each successive wave has built on the last, and together they comprise the supply side of the evidence architecture. To support the use of evidence demand side activities such as Evidence Needs Assessments and Use of Evidence Awards are proposed.