방법 비교

	AB 설계	ABA 설계	ABAB 설계	적응형 실험
분야	실험설계	실험설계	실험설계	실험설계
계열	Process / pipeline	Process / pipeline	Process / pipeline	Process / pipeline
기원 연도	1960s	1968	1960s (Sidman 1960; Baer et al. 1968)	1940s–1970s (sequential foundations); formalised in clinical and behavioural research by 1980s–2000s
창시자	Murray Sidman; Baer, Wolf & Risley	Montrose Wolf, Donald Baer, Todd Risley (applied behavior analysis tradition)	Murray Sidman; Baer, Wolf & Risley (applied behavior analysis formalization)	Abraham Wald (sequential analysis foundation); expanded by Robbins, Armitage, and others
유형	Single-subject experimental design	Single-subject experimental design	Single-subject experimental design	Experimental research design
원전	Sidman, M. (1960). Tactics of Scientific Research: Evaluating Experimental Data in Psychology. Basic Books.	Baer, D. M., Wolf, M. M., & Risley, T. R. (1968). Some current dimensions of applied behavior analysis. Journal of Applied Behavior Analysis, 1(1), 91–97.	Sidman, M. (1960). Tactics of Scientific Research: Evaluating Experimental Data in Psychology. Basic Books.	Chow, S. C., & Chang, M. (2008). Adaptive Design Methods in Clinical Trials. Chapman and Hall/CRC. ISBN: 978-1584886761
별칭	baseline-intervention design, AB single-case design, AB phase design	reversal design, withdrawal design, ABA withdrawal design	reversal design, withdrawal design, ABAB reversal, operant reversal design	adaptive design, response-adaptive randomization, adaptive trial, adaptive randomization
관련	4	4	4	5
요약	The AB design is the simplest single-subject experimental design, consisting of two sequential phases: a baseline phase (A) in which the target behavior is observed under natural conditions without intervention, followed by an intervention phase (B) in which the treatment or manipulation is introduced. Changes in the behavior's level, trend, or variability between phases are used to infer the effect of the intervention on the individual participant.	The ABA design is a single-subject experimental design that demonstrates experimental control through three sequential phases: a baseline phase (A1), an intervention phase (B), and a return-to-baseline withdrawal phase (A2). By removing the intervention in the final phase and observing whether behavior reverts toward baseline levels, researchers establish a functional relationship between the treatment and the target behavior for an individual participant.	The ABAB design is a single-subject experimental methodology that establishes causal control by repeatedly introducing and removing an intervention. A baseline phase (A) is followed by an intervention phase (B), then a return to baseline (A), and a second intervention phase (B), allowing the researcher to demonstrate that observed behavior changes are produced by the intervention rather than by coincidental factors.	An adaptive experiment is an experimental design in which pre-specified rules allow the protocol to be modified — such as reallocating participants to better-performing arms, stopping early for efficacy or futility, or changing sample size — based on accumulating interim data, while maintaining statistical validity. Adaptive designs are widely used in clinical trials, behavioural economics, and online platform testing to improve efficiency and ethics without sacrificing inferential rigour.