Rosenthal Robert, Rubin Donald B
U California.
Harvard U.
Psychol Methods. 2003 Dec;8(4):492-496. doi: 10.1037/1082-989X.8.4.492.
The purpose of this article is to propose a simple effect size estimate (obtained from the sample size, N, and a p value) that can be used (a) in meta-analytic research where only sample sizes and p values have been reported by the original investigator, (b) where no generally accepted effect size estimate exists, or (c) where directly computed effect size estimates are likely to be misleading. This effect size estimate is called r(equivalent) because it equals the sample point-biserial correlation between the treatment indicator and an exactly normally distributed outcome in a two-treatment experiment with N/2 units in each group and the obtained p value. As part of placing r(equivalent) into a broader context, the authors also address limitations of r(equivalent).
本文的目的是提出一种简单的效应量估计方法（根据样本量N和p值获得），该方法可用于：(a) 元分析研究中，原始研究者仅报告了样本量和p值；(b) 不存在普遍接受的效应量估计方法的情况；或 (c) 直接计算的效应量估计可能产生误导的情况。这种效应量估计被称为r（等效值），因为在每组有N/2个单位的双处理实验中，它等于处理指标与完全正态分布结果之间的样本点二列相关，以及获得的p值。作为将r（等效值）置于更广泛背景下的一部分，作者还讨论了r（等效值）的局限性。
