A psychometric evaluation of developmental dyslexia in italian children

A method for selecting poor readers from a wide sample of school children is described. A collective reading test and a spelling test were specially devised for the Italian language and were given to 969 subjects, within the age range of 8 to 10 years. The scores on these two tests were corrected for age and for scores on a culture-free intelligence test. Subjects performing worse than 95% of the population on both tests were considered as dyslexic. The validity of such a psychometric criterion is suggested by the following findings: (1) subjects who proved to be backward in reading and writing on the two collective tests were also found to be impaired on an individual reading test. (2) The two collective tests were performed at a very inferior level by a group of children diagnosed as dyslexic on a clinical basis. The main advantage of the psychometric method is to rule out the influence of intelligence on reading performance and to provide an objective criterion for identifying dyslexic children.