Several definitions of dyslexia revealed that reading deficits is the only common symptom among all of them (Doyle 1996), therefore, this paper's scope is focused more on such problems as related to dyslexia. Although varying in approach and interpretation of dyslexia, researches done by Beech (2005), Fisher & DeFries (2002), Habib (2000), Helland, Turid & Asbjornsen (2003), as well as those by Lachmanni & Geyer (2003). Needle, Fawcett & Nicolson (2006), Perry & Rice (1999), Davis & Braun (1995), Sawyer (2006), and Singleton (2005) invariably referred to reading deficit as common symptom of dyslexia. The same is true with those of Vellutino, Fletcher, Snowling, & Scanlon (2004).
Although references have been accorded to some researchers of dyslexia, the bulk of these discussions here have been sourced from Gardiola (2001) who has so far covered extensively the history of dyslexia and its genetic etiology or the study of its cause. The paper ends with the hope that with the recent proliferation of theories and studies now, the main genes influencing the development of reading and dyslexia will soon be known.
Bright solutions (2007) gives thre...
If a child's difficulty with reading could not be explained by low intelligence, poor eye sight, poor hearing, inadequate educational opportunities, or any other problem, then the child must be dyslexic. That definition, however, did nor please parents, teachers, or researchers.
Simple and revised definition. Accordingly, the simple definition says dyslexia is an inherited condition that makes it extremely difficult to read, write, and spell in one's native language, despite at least average intelligence. On the other hand, the revised definition from the International Dyslexia Association is that -
Dyslexia is a neurologically-based, often familial, disorder which interferes with the acquisition and processing of language. Varying in degrees of severity, it is manifested by difficulties in receptive and expressive language, including phonological processing, in reading, writing, spelling, handwriting, and sometimes in arithmetic.
Research definition. Finally, the research definition used by the National Institutes of Health is that -
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.
Organizational definitions. Dyslexia is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities