In this study, we aimed to determine the validity of the double-deficit hypothesis, which argues that reading difficulties arise due to inadequacies in phonological awareness and rapid naming, in relation to reading difficulties in a transparent language such as Turkish. Accordingly, children attending a kindergarten were assigned to four groups: a double-deficit group (n = 23), phonological awareness deficit group (n = 35), rapid naming deficit group (n = 29) or control group (n = 48) according to the scores they received on measures of phonological awareness and rapid naming. The performance of the groups in reading and reading comprehension was followed longitudinally from the first grade to the end of the second grade and were compared at four time points. On the basis of multivariate analysis of variance (MANOVA), it was determined that the double-deficit group performed worst in reading and reading comprehension tasks, and the control group performed best. While the reading and reading comprehension achievements of all groups increased over time, the findings suggest that the performance of groups with phonological awareness and rapid naming deficits differed significantly from the double-deficit group and the control group. This study, which examined the effects of the double-deficit hypothesis for Turkish-speaking children, offers a new approach to identifying children at risk of reading difficulties in early years and to planning appropriate interventions.

Keywords: Reading difficulties, Double-deficit hypothesis, Reading, Reading comprehension, Longitudinal analysis