השוואת שיטות

	ניסוי אקראי מבוזר מרובה-זרועות	ניסוי מבוקר אקראי באשכולות
תחום	תכנון ניסויים	תכנון ניסויים
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1990s–2000s (systematic formalization)	1978–1980s
הוגה השיטה	Building on cluster randomization (Donner & Klar) and multi-arm trial methods developed in clinical and public health research	Cornfield (1978); systematised by Donner and colleagues (1980s)
סוג	Experimental design	Experimental design
מקור מכונן	Donner, A., & Klar, N. (2000). Design and Analysis of Cluster Randomization Trials in Health Research. Arnold. ISBN: 978-0340691533	Donner, A., & Klar, N. (2000). Design and Analysis of Cluster Randomization Trials in Health Research. Arnold. ISBN: 978-0340652978
כינויים	multi-arm cluster RCT, cluster-randomized multi-group trial, multi-arm group-randomized trial, CRCT multi-arm	cluster RCT, group-randomized trial, community randomized trial, cluster-randomized experiment
קשורות	6	4
תקציר	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 cluster randomized controlled trial (cluster RCT) is an experimental design in which intact social or organisational groups — such as schools, clinics, villages, or workplaces — are randomly assigned to treatment conditions rather than individual participants. Outcomes are still measured at the individual level, but the unit of randomization is the cluster. This design is essential when an intervention is delivered to whole groups, when there is a risk of contamination between participants in the same setting, or when individual randomization is logistically or ethically impractical.