This study examined the Double-Deficit Hypothesis (DDH) by classifying students with dyslexia into four distinct groups, comparing group differences on text-level reading tasks, and examining group stability across one school year (fall to spring). Elementary students (N = 109) were administered measures of reading fluency, reading comprehension, and phonological processing across the school year. DDH group membership was determined by the presence of phonological awareness deficits (PD), naming speed deficits (NSD), double-deficits (DD) in both skills, or no deficits for typically developing (TD) readers. The McNemar test was used to determine the stability of DDH group membership. Analysis of covariance was used to compare DDH groups on text-level reading tasks at each time point after controlling for gender. Overall, reading profiles across the fall DDH groups were congruent with DDH theory, but instability was found in the reading patterns and group membership across time. Nearly half (47.71%) of participants changed DDH groups across the school year and reading skill differences between the single-deficit groups dissipated in the spring. Results provide partial support for the DDH subgroups. More research is needed to understand the utility of the DDH subtypes for future assessment and intervention practices.

这项研究通过将阅读困难的学生分为四个不同的组，比较了不同水平的课文阅读任务上的组差异，并检查了整个一学年（春季至春季）的组稳定性，从而研究了双重缺陷假说（DDH）。小学生（N= 109）在整个学年内对阅读流利度，阅读理解和语音处理进行了测量。DDH组的成员资格是由两种技能的语音意识缺陷（PD），命名速度缺陷（NSD），双重缺陷（DD）的存在或对于典型的（TD）阅读者没有缺陷来确定的。McNemar测试用于确定DDH组成员资格的稳定性。在控制性别之后，在每个时间点使用协方差分析比较DDH组在文本级别阅读任务上的作用。总体而言，秋季DDH组的阅读情况与DDH理论是一致的，但是在整个时间范围内，阅读模式和组成员身份均存在不稳定。近一半（47。在整个学年中，有71％的参与者改变了DDH组，而单赤字组之间的阅读技能差异在春季消失了。结果为DDH亚组提供了部分支持。需要更多的研究来了解DDH亚型在未来评估和干预实践中的作用。