This book reports a longitudinal study of a cohort of 3, 200 children who started first grade in 1976 in Bergen, Norway. Approximately 250 of these children had learning disabilities. This sample of learning disabled were studied and treated over an 8-year period. About 190 of the learning disabled children had dyslexia. In addition to collecting extensive psychological data on each of these dyslexic children, the Bergen study sought to diagnose and treat the various subtypes of manifest dyslexia. This comprehensive study demonstrated the seriousness of the problem, exemplified by the fact that the retarded children tended to show greater growth in reading and spelling in the primary grades than the dyslexics. The findings from this important study will have profound implications on the treatment of dyslexic children in the future.