Colliders, variables that serve as a common outcome of an independent and dependent variable, pose a major challenge in psychological research. Collider variables can induce bias in the estimation of a population relationship of interest when (a) the composition of a research sample is restricted by scores on a collider variable or (b) researchers adjust for a collider variable in their statistical analyses, as they might do for confounder variables. Both cases interfere with the accuracy and generalizability of statistical results. Despite their importance, however, collider effects remain relatively unknown in psychology. This tutorial article summarizes both the conceptual and the mathematical foundation for collider effects and their relevance to psychological research, and then proposes a method to correct for collider bias in cases of restrictive sample selection based on Thorndike's Case III adjustment (1982). Two simulation studies demonstrated Thorndike's correction as a viable solution for correcting collider bias in research studies, even when restriction on the collider variable was extreme and the selected sample size was as low as N = 100. Bias and relative bias results are reported to evaluate how well the correction equation approximates targeted population correlations under a variety of parameter conditions. We illustrate the application of the correction method to a hypothetical study of intelligence and conscientiousness, discuss the applicability of the method to more complex statistical models as a means of detection for collider bias, and provide code for researchers to apply to their own research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

中文翻译：

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纠正心理学研究中的碰撞效应和样本选择偏差。


碰撞变量是自变量和因变量的共同结果，对心理学研究提出了重大挑战。当（a）研究样本的组成受到对撞变量分数的限制或（b）研究人员在统计分析中调整对撞变量时，对撞变量可能会在估计感兴趣的总体关系时产生偏差，因为他们可能会这样做对混杂变量进行处理。这两种情况都会影响统计结果的准确性和普遍性。然而，尽管碰撞效应很重要，但它在心理学中仍然相对未知。本教程文章总结了碰撞效应的概念和数学基础及其与心理学研究的相关性，然后提出了一种基于桑代克案例 III 调整（1982）的限制性样本选择情况下校正碰撞偏差的方法。两项模拟研究证明，桑代克的校正是纠正研究中对撞机偏差的可行解决方案，即使对对撞机变量的限制非常严格并且所选样本量低至 N = 100。报告偏差和相对偏差结果以评估如何修正方程近似于各种参数条件下的目标总体相关性。我们说明了校正方法在智力和责任心的假设研究中的应用，讨论了该方法作为检测碰撞偏差的手段在更复杂的统计模型中的适用性，并为研究人员提供了应用于自己研究的代码。 （PsycInfo 数据库记录 (c) 2024 APA，保留所有权利）。