The characterization of an effect size is best made in reference to effect sizes found in the literature. A random-effects meta-analysis is the systematic synthesis of related effects from across a literature, producing an estimate of the distribution of effects in the population. We propose using the estimated mean and variance from a random-effects meta-analysis to inform the characterization of an observed effect size. The percentile of an observed effect size within the estimated distribution of population effects can describe the magnitude of the observed effect. Because there is uncertainty in the population estimates, we propose using the prediction distribution (used frequently to estimate the prediction interval in a meta-analysis) to serve as the reference distribution when characterizing an effect size. Doing so, the percentile of an observed effect and the limits of the effect size's 95% confidence interval within the prediction distribution are calculated. With numerous meta-analyses available including various outcomes and contexts, the presented method can be useful to many researchers and practitioners. We demonstrate the application of an easy-to-use Excel worksheet to automate these percentile calculations. We follow this with a simulation study evaluating the method's performance over a range of conditions. Recommendations (and cautions) for meta-analysts and researchers conducting a single study are provided. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

中文翻译：

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那么它比其他东西更好吗？使用随机效应荟萃分析的结果将效应大小的大小描述为百分位数。


效应大小的表征最好参考文献中的效应大小。随机效应荟萃分析是对文献中相关效应的系统综合，从而对效应在人群中的分布进行估计。我们建议使用随机效应荟萃分析的估计均值和方差来表征观察到的效应大小。群体效应估计分布内观察到的效应大小的百分位数可以描述观察到的效应的大小。由于总体估计存在不确定性，我们建议使用预测分布（经常用于估计荟萃分析中的预测区间）作为表征效应大小时的参考分布。这样做，可以计算观察到的效应的百分位数以及预测分布内效应大小的 95% 置信区间的限值。凭借大量可用的荟萃分析（包括各种结果和背景），所提出的方法对许多研究人员和从业者来说可能很有用。我们演示了如何应用易于使用的 Excel 工作表来自动执行这些百分位计算。我们随后进行了模拟研究，评估该方法在一系列条件下的性能。为进行单一研究的荟萃分析人员和研究人员提供了建议（和注意事项）。 （PsycInfo 数据库记录 (c) 2024 APA，保留所有权利）。