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.

群集随机实验被认为是可以确定教育治疗和干预措施的影响的黄金标准。必须做出的最重要的设计决策之一是确定学生和正在研究的群集的样本（例如，教室或教师或学校）的大小，以估算能力以产生预期的效果。目前，群集随机试验的设计很常见，仅能检测具有足够功率治疗的主要效果。这些研究错过了能够对治疗可能产生影响的有效评估以及治疗有效的条件（适度）的有效评估。这项研究将通过开发功率公式和软件来提高我们对聚类随机试验的理解，以测试多层次的审核和中介，以及这两个项目的组合。该项目将具有三个组成部分：1）。开发用于估算群集随机试验中多级适度，中介，中等调解和介导的统计能力的新公式； 2）。通过模拟评估和验证公式； 3）。在两个现有的软件程序中实现公式，即最佳设计加和PowerUp！。该项目将开发用于使用新分析的培训材料，并开发和进行研讨会，以将工具广泛传播到该领域。