Multilevel meta-analysis is an innovative synthesis technique used for the quantitative integration of effect size estimates across participants and across studies. The quantitative summary allows for objective, evidence-based, and informed decisions in research, practice, and policy. Based on previous methodological work, the technique results in powerful, unbiased, and precise effect size estimates. However, its use in practice is limited and its full potential is not yet fully understood. This article aims to bring the multilevel meta-analytic model closer to the applied researcher by introducing the technique at a conceptual level and discussing its full potential and relevance to the field. The procedure of multilevel meta-analysis is illustrated using a recent single-case meta-analytic dataset. Software codes, output tables, interpretations, and graphical displays of effect size estimates are given such that the reader can repeat the analysis independently.

中文翻译：

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研究证据的定量综合：多层次荟萃分析

多级荟萃分析是一种创新的合成技术，用于对参与者和研究之间的效应大小估计值进行定量整合。定量摘要允许在研究，实践和政策中做出客观，基于证据和知情的决定。根据先前的方法学工作，该技术可产生强大，无偏且精确的效果大小估算值。但是，其在实践中的使用受到限制，并且尚未完全理解其全部潜力。本文旨在通过在概念层面上介绍该技术，并讨论其全部潜力和与该领域的关联性，使多层次元分析模型更接近应用研究人员。使用最新的单例荟萃分析数据集说明了多级荟萃分析的过程。软件代码，输出表，解释，