Randomized single-case AB phase designs: Prospects and pitfalls
Randomized single-case AB phase designs: Prospects and pitfalls
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DOI：
10.3758/s13428-018-1084-x
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发表时间：
2019-12-01
影响因子：
5.4
通讯作者：
Onghena, Patrick
中科院分区：
文献类型：
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作者：
Michiels, Bart;Onghena, Patrick
在临床心理学和教育心理学等领域，单病例实验设计(SCED)越来越多地用于评估个体参与者的治疗和干预措施。AB相设计，又称间断时间序列设计，是实际应用中最基本的SCEDs之一。通过随机确定干预的起始点，可以将随机化包括在该设计中。在本文中，我们首先介绍了这种随机的AB期设计，并回顾了它的优缺点。其次，我们提出了一些与此设计相关的数据分析可能性和陷阱，并展示了随机化测试的使用如何缓解或补救其中的一些陷阱。第三，我们证明了在随机AB阶段设计中，当数据中存在意想不到的线性趋势时，随机化检验的I型误差是可控的。第四，我们报告了一项模拟研究的结果，该研究调查了在随机AB阶段设计中意外的线性趋势对随机化检验的功效的影响。讨论了这些结果对随机AB相设计分析的影响。我们的结论是，随机的AB期设计在实验上是有效的，但这些设计的功率仅在大的治疗效果和大的样本量下足够。对于小的治疗效应和小样本量，研究人员应该转向更复杂的阶段设计，如随机ABAB阶段设计或随机多基线设计。
Single-case experimental designs (SCEDs) are increasingly used in fields such as clinical psychology and educational psychology for the evaluation of treatments and interventions in individual participants. The AB phase design, also known as the interrupted time series design, is one of the most basic SCEDs used in practice. Randomization can be included in this design by randomly determining the start point of the intervention. In this article, we first introduce this randomized AB phase design and review its advantages and disadvantages. Second, we present some data-analytical possibilities and pitfalls related to this design and show how the use of randomization tests can mitigate or remedy some of these pitfalls. Third, we demonstrate that the Type I error of randomization tests in randomized AB phase designs is under control in the presence of unexpected linear trends in the data. Fourth, we report the results of a simulation study investigating the effect of unexpected linear trends on the power of the randomization test in randomized AB phase designs. The implications of these results for the analysis of randomized AB phase designs are discussed. We conclude that randomized AB phase designs are experimentally valid, but that the power of these designs is sufficient only for large treatment effects and large sample sizes. For small treatment effects and small sample sizes, researchers should turn to more complex phase designs, such as randomized ABAB phase designs or randomized multiple-baseline designs.