手法を比較

	ブロック化A/Bテスト	ランダム化比較試験 (RCT)
分野	実験計画法	実験計画法
系統	Process / pipeline	Hypothesis test
提唱年	1926 (blocking principle); 2000s–2010s (online A/B testing application)	1948
提唱者	R. A. Fisher (blocking principle); adapted to online A/B testing by industry practitioners	James Lind (early precursor, 1747); modern formulation: Austin Bradford Hill & Medical Research Council (1948)
種類	Randomized controlled experiment with variance reduction	Interventional comparative study
原典	Fisher, R. A. (1926). The arrangement of field experiments. Journal of the Ministry of Agriculture of Great Britain, 33, 503–513.	Schulz, K.F., Altman, D.G., Moher, D., for the CONSORT Group (2010). CONSORT 2010 Statement: Updated Guidelines for Reporting Parallel Group Randomised Trials. BMJ, 340, c332.
別名	block-randomized A/B test, stratified A/B test, blocked split test, block-design A/B experiment	RCT, randomised controlled trial, clinical trial, Randomize Kontrollü Çalışma (RCT) Tasarımı
関連	4	7
概要	A blocked A/B test is an experimental design that partitions units (users, subjects, or clusters) into homogeneous blocks before randomly assigning them to treatment A or treatment B within each block. Blocking reduces within-experiment noise by ensuring that known sources of variation — such as device type, geography, or user tenure — are balanced across conditions, yielding more precise estimates of the treatment effect than a simple unblocked A/B test.	A randomized controlled trial (RCT) is the gold standard experimental design in clinical and health research, in which participants are randomly allocated to a treatment group or a control group so that the effect of an intervention can be measured with the highest possible degree of internal validity. The modern parallel-group RCT was formalized by Austin Bradford Hill and the Medical Research Council in their landmark streptomycin trial of 1948, and its reporting is governed today by the CONSORT 2010 guidelines (Schulz et al., 2010).