The DSM-IV-TR criteria for a disorder of written expression is writing skills (as measured by a standardized test or functional assessment) that fall substantially below those expected based on the individual's chronological age, measured intelligence, and age-appropriate education, (Criterion A). This difficulty must also cause significant impairment to academic achievement and tasks that require composition of written text (Criterion B), and if a sensory deficit is present, the difficulties with writing skills must exceed those typically associated with the sensory deficit, (Criterion C).