Intensive summer intervention drives linear growth of reading skill in struggling readers
Donnelly, P. M., Huber, E., & Yeatman, J. D. (2019). Intensive summer intervention drives linear growth of reading skill in struggling readers. Frontiers in Psychology, 10, 1900. doi:10.3389/fpsyg.2019.01900
An achievement of reading research has been the development of intervention programs for struggling readers. Most intervention studies employ a pre-post design, to examine efficacy, but this precludes the study of intervention-driven growth. Determining the time-course of improvement is essential for cost-effective, evidence-based intervention decisions. The goal of this study was to (a) analyze reading growth curves during an intensive summer intervention program and (b) characterize factors that predict individual differences in growth. A cohort of 37 children (6-12y) with reading difficulties (N = 21 with dyslexia diagnosis) were enrolled in 160 hours of intervention. We collected behavioral measures over 4 sessions assessing decoding, oral reading fluency, and comprehension. Data were analyzed using mixed-effects modeling to characterize growth and the moderating effect of individual differences (age, IQ, phonological awareness, & initial reading skill). Longitudinal measurements revealed a linear dose-response relationship between hours of intervention and improvement in reading ability. Decoding skills showed substantial growth (Cohen’s d = 0.81 (WJ Basic Reading Skills)), with fluency and comprehension growing more gradually (d =0.35 (WJ Reading Fluency)). Multivariate analyses revealed a significant contribution of initial reading ability in predicting individual growth rates: This demonstrates the efficacy of intensive intervention for highly impaired readers.