期刊名称：Journal of Measurement and Evaluation in Education and Psychology
电子版ISSN：1309-6575
出版年度：2019
卷号：10
期号：2
页码：179-201
DOI：10.21031/epod.530642
语种：English
出版社：EPODDER
摘要：A review of literature covering the past decade indicates a shortage of cluster-randomized trials (CRTs) in education and psychology in Turkey,the gold standard that is capable of producing high-quality evidence for high-stake decision making when individual randomization is not feasible.Scarcity of CRTs is not only detrimental to collective knowledge on the effectiveness of interventions but also hinders efficient design of such studies as prior information is at best incomplete or unavailable.In this illustration,we demonstrate how to estimate variance parameters from existing data and transform them into standardized forms so that they can be used in planning sufficiently powered CRTs.The illustration uses publicly available software and guides researchers step by step via introducing statistical models,defining parameters,relating them to notations in statistical models and power formulas,and estimating variance parameters.Finally,we provide example statistical power and minimum required sample size calculations.
关键词：cluster-randomized trials;variance estimation;statistical power analysis;minimum required sample size
