Children with poor reading comprehension tend to have oral language weaknesses leading to the suggestion that poor language in the early years is a proximal cause of later reading comprehension difficulties. Yet, longitudinal studies have not been able to reliably predict which children go on to have comprehension weaknesses and evidence comprises small sample sizes and a narrow focus on language in isolation. In this registered report, we will examine early predictors of later outcomes using a sample of 879 children identified as having comprehension weaknesses at 9 years in the Avon Longitudinal Study of Parents and Children (ALSPAC). Study 1 will test whether they had language weaknesses at ages 15, 24, and 38 months relative to peers who did not go on to develop reading difficulties (n=4516). We will examine the extent to which preschool language measures predict later group outcomes, and whether early language risk is exacerbated by an impoverished language and communication environment. Study 2 builds on this multiple risk approach to examine broader cognitive predictors alongside language. Using a subsample of 125 children with comprehension weaknesses and 562 typically developing readers, we will ask whether the breadth (number) or depth (severity) of risk factors predict reading outcomes. Together, these findings will improve our understanding of who is at risk of later comprehension difficulty, and the breadth of support that may be necessary for successful intervention.
Identifying the prevalence and heterogeneity of reading comprehension difficulties in the ALSPAC sample