Randomized Controlled Trials: How Can We Know “What Works”?

“Evidence-based” methods, which most prominently include randomized controlled trials, have gained increasing purchase as the “gold standard” for assessing the effect of public policies. But the enthusiasm for evidence-based research overlooks questions about the reliability and applicability of experimental findings to diverse real-world settings. Perhaps surprisingly, a qualitative study of British educators suggests that they are aware of these limitations and therefore take evidence-based findings with a much larger grain of salt than do policy makers. Their experience suggests that the real world is more heterogeneous than the world imagined by evidence-based policy enthusiasts.