手法を比較

	多群間クロスオーバー実験	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	Mid-20th century; multi-arm extensions formalized by 1970s–1980s	1990s–2000s (clinical formalization); multi-arm concept implicit in ANOVA-era factorial designs
提唱者	Developed from early crossover trial methodology (Williams 1949; Cochran & Cox 1957)	Developed within clinical trials methodology; formalized by Parmar, Royston and colleagues (UK MRC CTU, early 2000s)
種類	Within-subject experimental design with multiple treatment arms	Experimental design
原典	Jones, B., & Kenward, M. G. (2003). Design and Analysis of Cross-Over Trials (2nd ed.). Chapman and Hall/CRC. ISBN: 978-1584883869	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 crossover trial, multi-period multi-treatment crossover, CMAT, multi-treatment crossover experiment	multi-arm trial, multiple-arm experiment, multi-group experiment, many-arm design
関連	5	5
概要	A crossover multi-arm experiment is a within-subject experimental design in which each participant receives three or more treatments (arms) across successive periods, with random assignment to sequence. Because every participant experiences all arms, the design eliminates between-subject variability from treatment comparisons, dramatically increasing statistical power for a given sample size. It is widely used in clinical pharmacology, psychology, agriculture, and behavioral research.	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.