Collaborative Research: Power Analyses for Moderator and Mediator Effects in Cluster Randomized Trials

协作研究：集群随机试验中调节剂和中介效应的功效分析

• 批准号: 1437679
• 负责人: Benjamin Kelcey
• 金额: $ 28.99万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1437679&HistoricalAwards=false
• 关键词: Collaborative; Research; Power; Analyses; Moderator

Cluster randomized experiments are considered the gold standards by which the impact of educational treatments and interventions can be determined. One of the most important design decisions that must be made is determining the size of the sample of students and the clusters under study (e.g., classrooms or teachers or schools) in order to estimate the power for an anticipated effect. Currently it is common for a cluster randomized trial to be designed to detect only the main effect of a treatment with adequate power. These studies miss out on being able to provide valid assessments of for whom a treatment might have an impact (mediation) and the conditions under which a treatment is effective (moderation). This research study will advance our understanding of cluster randomized trials by developing power formulas and software for tests of multi-level moderation and mediation, as well as the combination of the two.This project will have three components: 1). The development of new formulas for estimating the statistical power to detect multilevel moderation, mediation, moderated-mediation and mediated-moderation in cluster randomized trials; 2). Assess and validate the formulas through simulations; and, 3). Implement the formulas in two existing software programs, Optimal Design Plus and PowerUp!. The project will develop training materials for the use of the new analyses and develop and conduct workshops in order to disseminate the tool widely to the field.

整群随机实验被认为是确定教育治疗和干预措施影响的黄金标准。必须做出的最重要的设计决策之一是确定学生样本和所研究的集群（例如教室、教师或学校）的规模，以便估计预期效果的力量。目前，整群随机试验通常被设计为仅检测具有足够功效的治疗的主要效果。这些研究未能对治疗可能对谁产生影响（中介）以及治疗有效的条件（适度）提供有效的评估。这项研究将通过开发用于多级调节和中介测试以及两者结合的功效公式和软件，加深我们对整群随机试验的理解。该项目将包含三个组成部分：1)。开发新的公式来估计统计功效，以检测整群随机试验中的多级调节、中介、调节调节和调节调节； 2）。通过模拟评估和验证公式；以及，3)。在两个现有软件程序 Optimal Design Plus 和 PowerUp! 中实现这些公式。该项目将开发使用新分析的培训材料，并开发和举办研讨会，以便将该工具广泛传播到该领域。