The development of reading: as you seek so shall you find.

In this paper we critically examine different methods of investigation of reading development and reading disability. We argue that there is need for longitudinal studies of reading where a differential design allows assessment of the relative degree of involvement of associated skills. We then describe one study of this type. The results chart the development of children who become skilled readers and of those with generalized or specific reading disability. They also demonstrate the crucial effects of decisions regarding subject matching, test design, and measurement of differential abilities on the outcomes of such investigations. A cohort of 40 children was assessed for their abilities on 44 variables which involved reading, spelling, vocabulary, short-term memory (STM), visual skills, auditory-visual integration, language knowledge, rote knowledge and ordering ability as they developed from five to eight years old. Three groups were extracted at age eight on the basis of reading and IQ scores. Group A showed a relatively specific reading disability (high IQ, low reading), Group B were good readers of similarly high IQ, Group C showed a more generalized reading deficit whereby they were at the same level as Group A in reading but their IQ scores were low. The data were then searched retrospectively to describe the development of these patterns of ability from the very beginnings of reading acquisition. The children with specific reading retardation differed from their better-reading peers in terms of relatively few variables which concerned phonological segmentation, STM and naming. The children with generalized reading disability differed from their better-reading peers in almost every respect, but the strong discriminators concerned phonological processing. The children with specific reading disability differed from those with generalized reading disability in terms of abilities which involve visual processing. These patterns of ability were replicated at each age from five to seven years old.