Does intelligence make a difference? Spelling and phonological abilities in discrepant and non-discrepant reading and spelling disabilities.

Objectives: in an investigation involving, 1800 second-to-fourth graders, t he children were divided into three groups according to their reading and s pelling achievement and the results of a nonverbal intelligence test: child ren with average achievement in oral reading and spalling, and those with p oor achievements in both which were either discrepant or non-discrepant to their good-to-average scores on the intelligence test. Methods: Results for all three groups on a number of spelling tests were co mpiled to assess two component spelling skills: phonological recoding and a pplication of orthographical knowledge. Results: Children with either specific or nonspecific reading and spelling disabilities performed at the same level of phonologial recoding, while bot h groups were worse than younger children of average ability at the same sp elling level. Chidlren with IQ-discrepant reading and spelling disabilities hat, on the other hand, a certain advantage over children with the same nu mber of difficulties in spelling but a lower IQ on tasks rquiring a knowled ge of orthography. Though particularly evident in the lower grades, this ad vantage declined with advancing grade level. Additional comparison of the t hree groups in tests of phonological awareness and other phonological skill s revealed a similar pattern of great differences between the two groups of poor readers and spellers and the average children, but slight non-signifi cant differences between children with IQ-discrepant and non-discrepant rea ding and spelling disbilities.