Effectiveness of an early reading intervention for young children with intellectual disabilities who need or use augmentative and alternative communication on trajectories of decoding and sight word recognition: Study protocol for a cluster-randomized controlled factorial trial

Background Children with intellectual disabilities who need or use augmentative and alternative communication are often excluded from early reading instruction in both kindergarten and school. Behavioral challenges, lack of functional speech, and low expectations regarding reading acquisition may be contributing factors. Reading ability has a significant impact on the self-expression and social life of individuals who need or use augmentative and alternative communication. These individuals can acquire reading skills with a tailored curriculum designed to meet their needs. Research shows that phonological-based reading instruction can be beneficial for this population; however, no randomized controlled trials have evaluated early reading instructions both in kindergarten and first grade on developmental trajectories for these individuals. Methods This study will examine the effect of an early reading intervention on trajectories of decoding and sight word recognition for children with intellectual disabilities who need or use augmentative and alternative communication. The intervention will be implemented in kindergarten and first grade using a two-by-two factorial, randomized controlled trial. Kindergartens are randomized into one of four groups: (1) intervention in kindergarten and first grade, (2) intervention in kindergarten only, (3) intervention in first grade only, or (4) training-as-usual in both years. Each intervention lasts 37 weeks over the course of one academic year, with children aged 4–8 years receiving reading instruction delivered by special education teachers. The intervention uses Reading for All material, which is a phonological-based instruction targeting skills such as letter–sound knowledge, first-sound recognition, sound blending, shared reading, sight word recognition, and decoding. Outcomes will be assessed at multiple time points during each intervention year. Discussion The results of this RCT bring evidence of effectiveness of phonological reading instruction among children with intellectual disabilities who need or use augmentative and alternative communication on trajectories of decoding and sight word recognition from kindergarten to first grade. Moreover, our design tests the indirect effect of phonological awareness (formed by sound blending and first-sound recognition) and letter–sound knowledge on trajectories of decoding. Because the use of a control group that does not receive any intervention raises ethical concerns, all participants in the control group will be offered access to the reading material in second grade, outside the study context.