방법 비교

	다중 팔 실험	교차 무작위 대조 시험 (crossover RCT)
분야	실험설계	실험설계
계열	Process / pipeline	Process / pipeline
기원 연도	1990s–2000s (clinical formalization); multi-arm concept implicit in ANOVA-era factorial designs	1960s (Grizzle 1965 for statistical foundations); widely used in clinical research since the 1970s
창시자	Developed within clinical trials methodology; formalized by Parmar, Royston and colleagues (UK MRC CTU, early 2000s)	Early formalized by statisticians including Bradford Hill and colleagues in clinical trials; theoretical framework developed by Grizzle (1965) and later Senn (2002)
유형	Experimental design	Experimental within-subject design
원전	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.	Senn, S. (2002). Cross-over Trials in Clinical Research (2nd ed.). Wiley. ISBN: 978-0471496533
별칭	multi-arm trial, multiple-arm experiment, multi-group experiment, many-arm design	crossover RCT, crossover trial, within-subject RCT, AB/BA crossover design
관련	5	5
요약	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.	A crossover randomized controlled trial (crossover RCT) is an experimental design in which each participant receives all study interventions in a randomized sequence, separated by a washout period. Because every participant serves as their own control, within-subject variability is eliminated from the treatment comparison, yielding greater statistical power per participant than a parallel-group RCT of equal size.