方法对比

	Alternating Treatments Design	Single-Case Experimental Design
领域	Disability Studies	Disability Studies
方法族	Process / pipeline	Process / pipeline
起源年份	2013	2013
提出者	Single-case methodology tradition; design standards by Kratochwill et al.	Thomas R. Kratochwill and the What Works Clearinghouse single-case design panel
类型	Within-subject experimental pipeline comparing two or more conditions by rapid alternation	Within-subject experimental pipeline for evaluating interventions on individuals
开创性文献	Kratochwill, T. R., Hitchcock, J. H., Horner, R. H., Levin, J. R., Odom, S. L., Rindskopf, D. M., & Shadish, W. R. (2013). Single-case intervention research design standards. Remedial and Special Education, 34(1), 26-38.	Kratochwill, T. R., Hitchcock, J. H., Horner, R. H., Levin, J. R., Odom, S. L., Rindskopf, D. M., & Shadish, W. R. (2013). Single-case intervention research design standards. Remedial and Special Education, 34(1), 26-38.
别名	Multielement Design, Multiple-Schedule Design, Concurrent-Schedule Comparison Design, ATD	Single-Subject Experimental Design, N-of-1 Experimental Design, Single-Case Research Design, SCED
相关	3	3
摘要	The alternating treatments design (ATD), also called the multielement design, is a single-case experimental method that rapidly alternates two or more conditions or treatments within a single individual to compare their effects directly. Rather than running each treatment in a long block, the analyst switches between conditions in close succession — often session by session — in a counterbalanced or randomized order so that time, sequence, and setting do not favor one condition. The signature of an effect is a consistent vertical separation between the data paths of the conditions: when one treatment's outcomes reliably sit above another's across the alternation, the design attributes the difference to the treatment rather than to extraneous variables. Because comparison is built into the rapid alternation, the ATD can demonstrate differential effects quickly and without withdrawing an effective treatment to baseline. It fits squarely within the single-case design standards formalized by Kratochwill and colleagues in 2013, which treat systematic manipulation and replicated demonstrations as the basis for experimental control.	Single-case experimental design (SCED) is a family of rigorous within-subject experimental methodologies for evaluating whether an intervention causes change in an individual, widely used in rehabilitation, special education, and applied behavior analysis. Rather than averaging across a large sample, SCED measures a defined target behavior repeatedly across a baseline (A) phase and an intervention (B) phase, and infers a causal effect when the change is replicated at three or more different points in time within the same case. Internal validity is built into the design itself through systematic manipulation of the independent variable and repeated demonstrations of effect, not through a control group. The 2013 What Works Clearinghouse single-case design standards, formalized by Kratochwill and colleagues, codified what counts as a credible SCED, including requirements for systematic manipulation, at least three attempts to demonstrate an effect, and minimum data points per phase. SCED is the experimental backbone of evidence-based practice for individuals whose conditions, contexts, or low incidence make group designs impractical.