School of Psychology, Georgia Institute of Technology, J.S. Coon Bldg. 654 Cherry Street, Atlanta, GA 30332-0170, USA.
Behav Res Methods. 2011 Sep;43(3):692-700. doi: 10.3758/s13428-011-0076-x.
This article describes the RMediation package,which offers various methods for building confidence intervals (CIs) for mediated effects. The mediated effect is the product of two regression coefficients. The distribution-of-the-product method has the best statistical performance of existing methods for building CIs for the mediated effect. RMediation produces CIs using methods based on the distribution of product, Monte Carlo simulations, and an asymptotic normal distribution. Furthermore, RMediation generates percentiles, quantiles, and the plot of the distribution and CI for the mediated effect. An existing program, called PRODCLIN, published in Behavior Research Methods, has been widely cited and used by researchers to build accurate CIs. PRODCLIN has several limitations: The program is somewhat cumbersome to access and yields no result for several cases. RMediation described herein is based on the widely available R software, includes several capabilities not available in PRODCLIN, and provides accurate results that PRODCLIN could not.
本文描述了 RMediation 包，该包提供了多种方法来构建中介效应的置信区间 (CI)。中介效应是两个回归系数的乘积。在构建中介效应 CI 方面，乘积分布法是现有方法中统计性能最好的方法。RMediation 使用基于乘积分布、蒙特卡罗模拟和渐近正态分布的方法来生成 CI。此外，RMediation 还生成了中介效应的分布和 CI 的百分位数、分位数和图形。一个名为 PRODCLIN 的现有程序在《行为研究方法》中发表，被研究人员广泛引用和使用，以构建准确的 CI。PRODCLIN 有几个局限性：该程序访问起来有点麻烦，并且在几种情况下没有结果。本文描述的 RMediation 基于广泛使用的 R 软件，包含 PRODCLIN 中没有的几个功能，并提供了 PRODCLIN 无法提供的准确结果。
