An Analysis of Two Discrepancy-based Models and a Processing-Deficit Approach in Identifying Learning Disabilities

Abstract

The incidence of learning disabilities (LD) in a research center sample of 107 boys and 103 girls between 6 and 12 years of age was calculated using Wechsler IQ and Woodcock-Johnson cluster scores in a regression model (REG) and a reliability model (REL). The REL method identified LD three times more often than the REG method, and all those identified by REG were also identified by REL. When stratified by IQ, REG and REL identified similar percentages in the lowest IQ group; however, REG identified at a lower rate as IQ increased. All 87 children identified with reading disabilities (both REL-RD and REG-RD) were weak to a similar extent on phonemic awareness. Comorbid elevated attention ratings were found in 62% of children with RD; 26% had elevated attention ratings but no linguistic processing deficits, and 21% had at least one linguistic processing deficit but no attentionally suspect rating.