The LDDI is a rating scale designed to help psychologists, diagnosticians, LD specialists, speech-language pathologists and others identify intrinsic processing disorders and learning disabilities in students. A reliable and valid norm-referenced inventory, the LDDI is composed of six independent scales one for each of the areas listed in the definition by the U.S. Office of Education and the National Joint Committee on Learning Disabilities: Listening, Speaking, Reading, Writing, Mathematics and Reasoning. Each scale contains 15 easy-to-rate items. The items were generated after an extensive review of theoretical writings and empirical studies on learning disabilities, especially the literature that focused on the neuropsychological aspects of the disabilities. The appropriateness of the behaviours represented by the items was confirmed in a survey of experts in the field and by extensive research that is reported in the manual.