手法を比較

	クラスターランダム化フラクショナル要因実験	クラスターランダム化比較試験
分野	実験計画法	実験計画法
系統	Process / pipeline	Process / pipeline
提唱年	1950s (fractional factorial); 1980s-1990s (cluster-randomized extensions)	1978–1980s
提唱者	Box, Hunter & Hunter (fractional factorial foundations); Murray & colleagues (group-randomized trial methodology)	Cornfield (1978); systematised by Donner and colleagues (1980s)
種類	Experimental design (compound)	Experimental design
原典	Box, G. E. P., Hunter, J. S., & Hunter, W. G. (2005). Statistics for Experimenters: Design, Innovation, and Discovery (2nd ed.). Wiley. ISBN: 978-0471718130	Donner, A., & Klar, N. (2000). Design and Analysis of Cluster Randomization Trials in Health Research. Arnold. ISBN: 978-0340652978
別名	CR-FFE, cluster-randomized fractional factorial design, group-randomized fractional factorial trial, CRFFD	cluster RCT, group-randomized trial, community randomized trial, cluster-randomized experiment
関連	5	4
概要	A cluster-randomized fractional factorial experiment combines two design principles: randomization is applied to intact groups (clusters such as schools, clinics, or communities) rather than individuals, and only a carefully chosen fraction of all possible factor-level combinations is tested. This pairing makes it practical to screen or evaluate multiple intervention components simultaneously in settings where individual randomization is infeasible, while keeping the number of required clusters manageable.	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.