Abstract
Combining data from a series of three planned, consecutive independent randomized controlled trials (RCTs), the present study investigates two literacy interventions for preschool children with autism spectrum disorder (ASD). For the first cohort, children were randomized to interactive book reading treatment (IBR)or a business-as-usual (BAU) control condition; in Cohort 2, children were randomized to phonological awareness treatment (PA)or BAU; in Cohort 3, children were randomized to IBR or PA. Both treatments were implemented weekly in the classroom from November to May. Combined across cohorts, data from n =47 IBR, n =42 PA, and n =44 BAU students from 57 classrooms in 8 districts were available for analysis. Model results showed that IBR had significantly greater pretest-posttest gains than the sample mean on expressive vocabulary and listening comprehension (d*=0.29 and 0.30), whereas PA had significantly greater phonological awareness gains (d*=0.39).