An emerging body of research suggests that incorporating randomization schemes in single-case research designs strengthens study internal validity and data evaluation. The purpose of this study was to test the utility and feasibility of a randomized alternating-treatment design in an investigation that compared the combined effects of vocabulary instruction and the paraphrasing strategies on expository comprehension of six students with reading difficulties. We analyzed the data using three types of randomization tests as well as visual analysis. The visual analysis and randomization tests confirmed the additional benefit of vocabulary instruction on expository comprehension for one student. However, the effects were not replicated across the other five students. We found that proper randomization schemes can improve both internal validity and data analysis strategies of the alternating-treatment design.

中文翻译：

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使用随机交替治疗设计比较两种阅读干预的效果

一项新兴研究表明，将随机化方案纳入单案例研究设计可加强研究的内部有效性和数据评估。本研究的目的是在一项调查中测试随机交替处理设计的实用性和可行性，该调查比较了词汇教学和释义策略对六名阅读困难学生的说明性理解的综合影响。我们使用三种类型的随机化测试以及视觉分析来分析数据。视觉分析和随机化测试证实了词汇教学对一名学生的说明性理解的额外好处。然而，这些效果并没有在其他五名学生身上复制。