This paper reviews 20 studies that investigated the internal or external validity of various subtypes of autistic spectrum disorders. At least three groups could be distinguished from autism on clinical grounds: an Asperger syndrome subtype, and two atypical subtypes characterized by either low intelligence quotient or high intelligence quotient.…

This response to a paper by Linda Siegel (EC221505) on the relationship between Intelligence Quotient and learning disabilities addresses the differences between classification and identification, limitations in Siegel's conceptualization of intelligence, and the representation of the language and learning domains subsumed within the learning…

Forty normal readers and 50 dyslexic children (age 9-14) were matched on reading level and intelligence quotient and tested. Analysis revealed 3 major subgroups: specific deficit in phonological processing of print (52 percent), deficits in processing both the phonological and orthographic features of printed words (24 percent), and phonological…

Issues raised in responses to Linda Siegel's paper (EC221505) on the relationship between intelligence test scores and learning disabilities are addressed. Discussed are the nature of intelligence, classification of learning disabilities by discrepancy between intelligence test scores and achievement scores, the existence of learning disabilities,…

A study investigated the effects of nonverbal and verbal classification abilities on reading comprehension. Subjects, 104 fourth grade students, were tested on three measures of classification skill (a shifting of criteria task, a free sorting task, and a three-level hierarchical classification task) and on a measure of recall of relevant story…