方法对比

	Crossover Multi-Arm Experiment	自适应实验
领域	实验设计	实验设计
方法族	Process / pipeline	Process / pipeline
起源年份	Mid-20th century; multi-arm extensions formalized by 1970s–1980s	1940s–1970s (sequential foundations); formalised in clinical and behavioural research by 1980s–2000s
提出者	Developed from early crossover trial methodology (Williams 1949; Cochran & Cox 1957)	Abraham Wald (sequential analysis foundation); expanded by Robbins, Armitage, and others
类型	Within-subject experimental design with multiple treatment arms	Experimental research design
开创性文献	Jones, B., & Kenward, M. G. (2003). Design and Analysis of Cross-Over Trials (2nd ed.). Chapman and Hall/CRC. ISBN: 978-1584883869	Chow, S. C., & Chang, M. (2008). Adaptive Design Methods in Clinical Trials. Chapman and Hall/CRC. ISBN: 978-1584886761
别名	multi-arm crossover trial, multi-period multi-treatment crossover, CMAT, multi-treatment crossover experiment	adaptive design, response-adaptive randomization, adaptive trial, adaptive randomization
相关	5	5
摘要	A crossover multi-arm experiment is a within-subject experimental design in which each participant receives three or more treatments (arms) across successive periods, with random assignment to sequence. Because every participant experiences all arms, the design eliminates between-subject variability from treatment comparisons, dramatically increasing statistical power for a given sample size. It is widely used in clinical pharmacology, psychology, agriculture, and behavioral research.	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.