The development of two forms of reading disability

The Castles and Coltheart regression method was used in a sample of 153 Grade 3 children to identify those with phonological and surface dyslexia. A third group of double dyslexics was also found. These three groups and the normally-achieving children were first compared on a battery of Grade 3 reading, spelling and phonological processing measures. In the second set of analyses, the performance of the four groups over the previous three years was compared. Results indicate that children with phonological and surface dyslexia show distinct patterns of performance from early in kindergarten.