A statistical study of specific dyslexia: Characteristics and syndrome patterns

Clinically significant variables reported in the literature on specific dyslexia were experimentally studied in matched group design. The experimental and control groups consisted of 32 and 23 third and fourth grade children respectively. The children came from families in the middle to above average socioeconomic classification. They were free of medical problems and personality-emotional disturbances, and they had above average intelligence. Selection variables, 10 in all, were statistically held constant with the exception of reading and spelling. The experimental group was one or more years below grade level on reading and spelling and the control group was at or above grade level on reading and spelling. The two groups were compared on 197 variables in the following areas: (a) intelligence (WISC); (b) education-- reading, writing, spelling, and arithmetic; (c) visual perception; (d) auditory perception; (e) speech; (f) psychoneurological; (g) neurological; (h) EEG; (i) medical history; and (j) familial history of language disability. The data were analyzed by means of simple analysis of variance, intercorrelation of significant variables, factor analysis, hierarchical grouping analysis, and analysis of variance of variables used in the hierarchical grouping analysis. These procedures produced 43 significant variables, 14 factors, and three syndrome patterns of specific dyslexia.