What is dyslexia?

Background


Dyslexia is a type of Learning Disability.  The Dyslexia SPELD Foundation (DSF) defines a Learning Disability as resulting from "an impairment in one or more of the psychological processes related to learning".  The DSF states that, significantly, the difficulties experienced by a student with a specific learning disability are unexpected in relation to their other skills. The DSF  goes on to comment that "these difficulties are likely to be resistant to intervention and will persist into adulthood."  Thus, it is a different situation to students experiencing learning difficulties as the result of one of the following, as cited by the DSF: intellectual disability, physical or sensory deficits, emotional or behavioural difficulties, inadequate environmental experiences, inappropriate educational opportunities, ineffective instruction or a primary difficulty in maintaining attention and concentration.

In The SAGE Handbook of Dyslexia (2008, p.294 ) the article by Siegel and Lipka, highlights the fact that "great confusion exists" around a common operational definition of Learning Disabilities.  In this article they draw attention to the need  for a universally accepted definition in order for there to be "accurate diagnosis and classification of students" (2008, p.294).    Siegal and Lipka conclude that "Learning Disabilities should be defined in terms of the domain of the deficit" (2008, p. 307).  The International Dyslexia Association (IDA)  lists the most common learning disabilities as below, students may present with one or more.
  • Dyslexia - a language based learning disability
  • Dyscalculia - a mathematical disability (LDOnline factsheet)
  • Dysgraphia - a neurological-based writing disability (IDA factsheet)

It is important to comment on a misconception that dyslexia does not exist.  
Extensive research has led to the following countries recognising dyslexia by law: England, Wales, Scotland, Northern Ireland and the USA. In Australia dyslexia is recognised under the Educational Standards listed within the Federal Governments Anti Discrimination Act, to find out more look at the recognition of dyslexia in Australia To listen or read about leading experts opinions in the field of dyslexia go to the 2010 World Dyslexia Forum website.

Defining dyslexia


A look at the Greek origin of 'dyslexia' in the Concise Oxford English Dictionary (2008) tells us that someone with dyslexia has difficulty with words:
                                                dys = difficulty
                                                lexia = words
However, most definitions of dyslexia encompass more than this.  The
most commonly accepted definition of dyslexia is that adopted by the International Dyslexic Association (IDA) and used by the National Institute of Child Health and Human Development (NICHD):

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.

Key points


Dyslexia is a specific type of Learning Disability related to reading and spelling normally resulting from a difficulty with the phonological component of language.

In the video below, Susan J. Schwartz  MA Ed, Senior Director, Learning and Diagnostic Center of the Child Mind Institute defines dyslexia and explains some of the most common characteristics.