השוואת שיטות

	ניסוי מבוקר אקראי חסום	ניסוי מבוקר אקראי אדפטיבי
תחום	תכנון ניסויים	תכנון ניסויים
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1920s (Fisher's blocking principle); applied to RCTs from the 1940s onward	1980s–2000s (formalized; earlier sequential testing roots from Wald, 1947)
הוגה השיטה	R. A. Fisher (blocking principle); systematic RCT application by Bradford Hill and later Pocock, Friedman et al.	Donald Berry and others; foundational adaptive trial methods developed through 1980s–2000s biostatistics literature
סוג	Experimental design	Experimental design — adaptive variant of RCT
מקור מכונן	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2010). Fundamentals of Clinical Trials (4th ed.). Springer. ISBN: 978-1441915856	Chow, S.-C., & Chang, M. (2008). Adaptive Design Methods in Clinical Trials. Chapman & Hall/CRC. ISBN: 978-1584887690
כינויים	blocked RCT, block-randomized trial, stratified block randomization trial, permuted block randomization	Adaptive RCT, Response-adaptive RCT, Adaptive clinical trial, Platform trial
קשורות	5	6
תקציר	A blocked randomized controlled trial (blocked RCT) uses permuted-block randomization to ensure that treatment groups remain balanced in size — and optionally in key characteristics — throughout recruitment. Within each block of fixed or randomly varied size, all treatment allocations are present in equal numbers, so imbalance cannot accumulate even if the trial is stopped early. This makes blocked RCTs the standard randomization approach in clinical and behavioral intervention research.	An adaptive randomized controlled trial (adaptive RCT) is an experimental design in which pre-specified rules allow modifications to the trial while it is ongoing — such as changing allocation ratios, dropping underperforming arms, or stopping early for efficacy or futility — based on accumulating interim data. These adaptations are planned before the trial starts and governed by statistical rules to preserve Type I error control and validity.