Slingerland® Institute for Literacy


The term dyslexia is used to describe an “unexpected” difficulty with reading or writing. Throughout history, there have been many different definitions of dyslexia, causing confusion for families, students, and professionals. This inconsistency and confusion has resulted in avoidance of the term dyslexia in favor of less specific terms such as “reading disability” or “learning disability.” Research has provided quite specific criteria for a diagnosis for dyslexia. Terminology for a medical diagnosis may vary from the terminology used by educational systems to qualify students for individual education plans.

Alternative TextIDA 2002 Definition (Definition of Dyslexia Adopted by the IDA Board of Directors, Nov. 12, 2002) 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 impeded growth of vocabulary and background knowledge.

Here is a link to the International Dyslexia Association’s (IDA) characteristics of dyslexia:

The IDA provides a list of fact sheets which will further shed light on dyslexia and some of the resources available to you. Dyslexia Fact Sheets

Slingerland® Institute for Literacy
PO Box 1648, Bellevue, WA 98009 US
Phone: (425) 453-1190
Fax: (425) 635-7762