Lessons from Research on Dyslexia: Implications for a Classification System for Learning Disabilities

Specific reading disability/dyslexia is examined as the one type of learning disability for which research results are complete and consistent enough to suggest a model. The implications of this model are then considered for all achievement domains and a total of three types of learning disabilities (LD) emerge—specific language impairment, specific reading disability/dyslexia, and specific math disability. When the core symptoms and the secondary symptoms for these types of learning disabilities are considered separately, it becomes evident that these three types of learning disabilities can account for discrepancies in all of the academic domains included in federal and state definitions of LD. This resulting classification system links the findings from recent LD research, syndromes from neuropsychology, and the criteria that school districts are mandated to operationalize. The implications of the proposed classification system are discussed in relation to prevalence, diagnosis, and intervention.