Feingold Alan
Oregon Social Learning Center.
Quant Method Psychol. 2019;15(2):96-111. doi: 10.20982/tqmp.15.2.p096.
Although Cohen's and the growth modeling analysis (GMA) from linear models are common standardized effect sizes used to convey treatment effects, popular statistical software packages do not include them in their standard outputs. This article demonstrated the use of statistical software with user-prescribed parameter functions (e.g., Mplus) to produce for treatment effects from both classical analysis and GMA--along with their associated standard errors (s) and confidence intervals (CIs). A Monte Carlo study was conducted to examine bias in the and CI for GMA obtained with Mplus and found that both estimates were more accurate when calculated by the software with the standard bootstrap than with the delta method, but the delta method estimates were less biased than respective estimates from extant post hoc equations. Thus, users of many statistical software packages (including SAS, R, and LISREL) should obtain or GMA and associated CIs directly. Researchers employing less versatile software--and meta-analysts including s and GMA s in their syntheses of treatment effects--should continue to use the conventional post hoc equations. Biases in s and CIs for effect sizes obtained with them are ignorable and point estimates of and GMA are the same whether obtained directly from the software or with post hoc equations.
尽管科恩系数以及线性模型中的增长模型分析（GMA）是用于传达治疗效果的常见标准化效应量，但流行的统计软件包在其标准输出中并未包含这些内容。本文展示了使用具有用户指定参数函数的统计软件（例如Mplus）来生成经典分析和GMA的治疗效果——以及它们相关的标准误（s）和置信区间（CI）。进行了一项蒙特卡罗研究，以检验使用Mplus获得的GMA的效应量和CI中的偏差，结果发现，当通过具有标准自助法的软件进行计算时，这两种估计比使用德尔塔法更准确，但德尔塔法的估计偏差小于现有事后方程的相应估计。因此，许多统计软件包（包括SAS、R和LISREL）的用户应直接获取效应量或GMA以及相关的CI。使用功能较不通用软件的研究人员——以及在治疗效果综合分析中纳入标准误和GMA效应量的元分析人员——应继续使用传统的事后方程。使用这些方程获得的效应量的标准误和CI中的偏差可忽略不计，并且直接从软件或通过事后方程获得的效应量和GMA的点估计是相同的。
