So sánh phương pháp

	Thiết kế AB bị chặn	Thử nghiệm kiểm soát ngẫu nhiên theo khối (Blocked Randomized Controlled Trial)
Lĩnh vực	Thiết kế thí nghiệm	Thiết kế thí nghiệm
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1970s–1980s (systematic development of blocked randomization in single-case research)	1920s (Fisher's blocking principle); applied to RCTs from the 1940s onward
Người khởi xướng	Based on Fisher's randomized block principle (1926) applied to single-case AB designs	R. A. Fisher (blocking principle); systematic RCT application by Bradford Hill and later Pocock, Friedman et al.
Loại	Single-subject experimental design with blocking	Experimental design
Công trình gốc	Edgington, E., & Onghena, P. (2007). Randomization Tests (4th ed.). Chapman and Hall/CRC. ISBN: 978-1584885894	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
Tên gọi khác	blocked AB single-case design, randomized block AB design, AB design with blocking, blocked baseline-treatment design	blocked RCT, block-randomized trial, stratified block randomization trial, permuted block randomization
Liên quan	6	5
Tóm tắt	The Blocked AB Design applies the logic of randomized block experimental design to the classic single-subject AB framework. Observation sessions are organized into blocks — matched sets of time points or contextual units — and the assignment of baseline (A) and treatment (B) phases is randomized within each block. This controls for nuisance time-based variability while preserving the interpretive simplicity of the fundamental two-phase single-case structure.	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.