How persistent is reading disability? Individual growth curves in reading

Abstract

This paper addresses a critical theoretical issue concerning the developmental course of reading disability. Various models have been suggested on how reading ability develops for children with reading disabilities. The lag model states that poor readers are just slow starters who will catch up as they mature. The alternative view, the deficit model, is that poor reading is a more persistent condition. In order to study these hypotheses individual growth curves, on the basis of a word recognition test (the Wordchains test), will be presented. Based on two screening tests of word reading together with teacher ratings, reading-disabled (RD) children (65 boys and 18 girls) were selected from 2165 children in grade 2. A control group of non-disabled children was carefully matched with the RD children on gender, school class and non-verbal cognitive ability. The children were followed over a period of 7 years, until grade 9 at the end of compulsory schooling. For each child a linear growth function was estimated. Most of the children with early reading problems were still far behind the normal readers by the end of the compulsory school period. The gap between children with reading disability and the control group tended to increase despite extensive intervention. In summary, three out of five early identified RD children were stable poor readers. One small subgroup showed a lag effect and had reached the average level at grade 9. Thus a deficit model seemed more appropriate, at least for a large majority of children with early reading disability. Copyright © 1999 John Wiley & Sons, Ltd.