ABSTRACT Within evidence-based education, results from randomised controlled trials (RCTs), and meta-analyses of them, are taken as reliable evidence for effectiveness – they speak to “what works”. Extending RCT results requires establishing that study samples and settings are representative of the intended target. Although widely recognised as important for drawing causal inferences from RCTs, claims regarding representativeness tend to be poorly evidenced. Strategies for demonstrating it typically involve comparing observable characteristics (e.g., race, gender, location) of study samples to those in the population of interest to decision makers. This paper argues that these strategies provide insufficient evidence for establishing representativeness. Characteristics typically used for comparison are unlikely to be causally relevant to all educational interventions. Treating them as evidence that supports extending RCT results without providing evidence demonstrating their relevance undermines the inference. Determining what factors are causally relevant requires studying the causal mechanisms underlying the interventions in question.

中文翻译：

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代表性在循证教育中的关键作用

摘要在基于证据的教育中，随机对照试验（RCT）的结果以及它们的荟萃分析被视为有效性的可靠证据–它们说“行之有效”。扩展RCT结果需要确定研究样本和设置可以代表预期的目标。尽管被广泛认为对于从RCT中得出因果推论很重要，但有关代表性的主张却证据不足。证明它的策略通常包括将研究样本的可观察特征（例如种族，性别，位置）与决策者感兴趣的种群进行比较。本文认为，这些策略为建立代表性提供了不足的证据。通常用于比较的特征不太可能与所有教育干预措施因果相关。将它们视为支持扩展RCT结果的证据而没有提供证明其相关性的证据破坏了推论。要确定哪些因素是因果相关的，就需要研究这些干预措施背后的因果机制。