השוואת שיטות

	ניסוי מרובה זרועות	ניסוי פקטוריאלי
תחום	תכנון ניסויים	תכנון ניסויים
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1990s–2000s (clinical formalization); multi-arm concept implicit in ANOVA-era factorial designs	1926–1935
הוגה השיטה	Developed within clinical trials methodology; formalized by Parmar, Royston and colleagues (UK MRC CTU, early 2000s)	Ronald A. Fisher
סוג	Experimental design	Quantitative experimental design
מקור מכונן	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.	Fisher, R. A. (1935). The Design of Experiments. Oliver and Boyd.
כינויים	multi-arm trial, multiple-arm experiment, multi-group experiment, many-arm design	factorial design, factorial ANOVA design, multi-factor experiment, crossed-factor design
קשורות	5	6
תקציר	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 factorial experiment is an experimental design in which two or more independent variables (factors) are manipulated simultaneously, and every combination of their levels is tested. Introduced by Ronald Fisher in the 1920s–1930s, it is the standard approach whenever a researcher needs to detect not only the main effect of each factor but also whether the effect of one factor depends on the level of another — the interaction effect.