The Reading Comprehension and Vocabulary Knowledge of Children With Poor Reading Comprehension Despite Adequate Decoding: Evidence From a Regression-Based Matching Approach

The present study examined the reading comprehension and receptive vocabulary skills of children with poor reading comprehension despite adequate decoding using a regression-based matching technique. Participants included five cohorts of children who were identified as typical readers (N = 70,493 - 75,553) or as children with specific reading comprehension difficulties (N = 480 - 8,717). Across cohorts, children with specific reading comprehension difficulties exhibited oral language difficulties based on a measure of vocabulary; however, the observed weakness in vocabulary was not as severe as their reading comprehension difficulties. Results from the regression-based matching technique suggested that the vocabulary weakness for these children is better characterized as a developmental delay rather than a developmental deficit. This outcome also emerged when more stringent criteria were used to identify subgroups of readers. Although children with poor reading comprehension despite adequate decoding have a weakness in at least one aspect of oral language, their oral language weakness does not account for the severity of their reading comprehension difficulties. Theoretical and practical implications are discussed. Educational Impact and Implications Statement The present investigation examined the reading comprehension and receptive vocabulary skills of five cohorts of children who were identified as having poor reading comprehension despite adequate word reading skills. Across cohorts, children with reading comprehension problems had a weakness in receptive vocabulary knowledge; however, this weakness was less severe than their reading comprehension problem. Results also suggested that the observed vocabulary weakness was developmentally delayed, indicating that it is better characterized as a correlate rather than a cause of children's reading comprehension problems. Although children with poor reading comprehension despite adequate word reading skills have a weakness in at least one aspect of oral language, this weakness does not account for the severity of their reading comprehension difficulties.