Phonological Processing and Word Reading in Typically Developing and Reading Disabled Children:Severity Matters

This chapter concerns the word reading predictive values and the dynamics of alphanumeric rapid automatized naming (RAN) and phonemic awareness (PA) in the general population of Dutch elementary school–aged children (grades 3 through 6). A composite index of word reading based on standardized tests of real words and pseudowords was used to dichotomously classify a total of 1,598 children aged 7-14 years old for eight different cut-off points, four indicating (very) poor reading and four indicating (very) good reading performance. Phonological processing was assessed by standardized tests measuring PA and RAN. Analysis of relative operating characteristics (ROC) and analysis of variance were used to evaluate the differential and combined effectiveness of these tests in predicting group membership across the criteria for word reading skill. Results indicated substantial effect sizes for both types of phonological processing. Although the combination of RAN and PA proves to have the highest predictive values for word reading, the relative contribution of RAN increases with word reading skill, indicating more lexically based processing. This finding is in line with the assumption of increasing lexical access speed with reading development. This was particularly true for the excellent readers, where lexical access speed proved to be the dominant mode due to the diminished impact of sub-lexical processing. In contrast, more sub-lexically based processing was observed in reading-disabled children with accrued effect sizes for the more severely impaired readers. Theoretical and practical implications are discussed