手法を比較

	クラスターランダム化多腕試験	多群実験
分野	実験計画法	実験計画法
系統	Process / pipeline	Process / pipeline
提唱年	1990s–2000s (systematic formalization)	1990s–2000s (clinical formalization); multi-arm concept implicit in ANOVA-era factorial designs
提唱者	Building on cluster randomization (Donner & Klar) and multi-arm trial methods developed in clinical and public health research	Developed within clinical trials methodology; formalized by Parmar, Royston and colleagues (UK MRC CTU, early 2000s)
種類	Experimental design	Experimental design
原典	Donner, A., & Klar, N. (2000). Design and Analysis of Cluster Randomization Trials in Health Research. Arnold. ISBN: 978-0340691533	Royston, P., Parmar, M. K. B., & Qian, W. (2003). Novel designs for multi-arm clinical trials with survival outcomes with an application in ovarian cancer. Statistics in Medicine, 22(14), 2239–2256.
別名	multi-arm cluster RCT, cluster-randomized multi-group trial, multi-arm group-randomized trial, CRCT multi-arm	multi-arm trial, multiple-arm experiment, multi-group experiment, many-arm design
関連	6	5
概要	A cluster randomized multi-arm experiment assigns intact groups — such as schools, clinics, or villages — rather than individuals to three or more experimental conditions simultaneously. Randomization occurs at the cluster level to prevent contamination between arms, while the multi-arm structure allows simultaneous evaluation of several interventions against a common control or each other, improving efficiency over a series of two-arm studies.	A multi-arm experiment simultaneously compares three or more treatment or intervention conditions — each called an arm — against a shared control or against one another. By testing multiple alternatives in a single study, it yields more information per participant than running separate two-group experiments sequentially, while controlling the overall Type I error rate through pre-specified comparison strategies.