DYSLEXIA:
Dyslexia is a specific learning disability that is neurological in origin.
It is characterized by difficulties with accurate and/or fluent word recognition, and by poor spelling and decoding abilities.
These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction.
Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge.
This Definition was adopted in 2002 by the National Institute of Child Health and Human Development (NICHD)
According to various sources, dyslexia affects approximately 10% of the population. Dyslexia is a language processing difficulty.
The NCLD Definition
Learning disabilities is a general term that refers to a heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical skills.
These disorders are intrinsic to the individual, presumed to be due to central nervous system dysfunction, and may occur across the life span. Problems in self-regulatory behaviors, social perception, and social interaction may exist with learning disabilities but do not, by themselves, constitute a learning disability.
Although learning disabilities may occur concomitantly with other disabilities (e.g., sensory impairment, mental retardation, serious emotional disturbance), or with extrinsic influences (such as cultural differences, insufficient or inappropriate instruction), they are not the result of those conditions or influences (NJCLD, 1990).
The Five Constructs
1. Learning disabilities are heterogeneous, both within and across individuals. Intraindividual differences involve varied profiles of learning strength and need and/or shifts across the life span within individuals. Interindividual differences involve different manifestations of learning disabilities for different individuals.
2. Learning disabilities result in significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, and/or mathematical skills. Such difficulties are evident when an individual's appropriate levels of effort do not result in reasonable progress given the opportunity for effective educational instruction and with the recognition that all individuals learn at a different pace and with differing effort. Significant difficulty cannot be determined solely by a quantitative test score.
3. Learning disabilities are intrinsic to the individual. They are presumed to be related to differences in central nervous system development. They do not disappear over time, but may range in expression and severity at different life stages.
4. Learning disabilities may occur concomitantly with other disabilities that do not, by themselves, constitute a learning disability. For example, difficulty with selfregulatory behaviors, social perception, and social interactions may occur for many reasons. Some social interaction problems result from learning disabilities; others do not. Individuals with other disabilities, such as sensory impairments, attention deficit hyperactivity disorders, mental retardation, and serious emotional disturbance, may also have learning disabilities, but such conditions do not cause or constitute learning disabilities.
5. Learning disabilities are not caused by extrinsic influences. Inconsistent or insufficient instruction or a lack of instructional experience cause learning difficulties, but not learning disabilities. However, individuals who have had inconsistent or insufficient instruction may also have learning disabilities. The challenge is to document that inadequate or insufficient instruction is not the primary cause of a learning disability.
Individuals from all cultural and linguistic backgrounds may also have learning disabilities; therefore, assessments must be designed acknowledging this diversity in culture and language, and examiners who test children from each background must be sensitive to such factors and use practices that are individualized and appropriate for each child.