Dyslexia means a disorder of constitutional origin manifested by a difficulty in learning to read, write, or spell, despite conventional instruction, adequate intelligence, and sociocultural opportunity (not a language difference, inconsistent attendance, and/or lack of experiential background). The primary difficulties of a student identified as having dyslexia occur in phonemic awareness and manipulation, single-word decoding, reading fluency, and spelling. Secondary consequences of dyslexia may include difficulties in reading comprehension and/or written expression. These difficulties are unexpected for the student's age, educational level, or cognitive abilities. Additionally, there is often a family history of similar difficulties.

The following are the primary reading/spelling characteristics of dyslexia:
* difficulty reading real words in isolation
* difficulty accurately decoding nonsense words
* slow, inaccurate, or labored oral reading (lack of reading fluency)
* difficulty with learning to spell
The reading/spelling characteristics are the results of difficulty with the following:
* the development of phonological awareness, including segmenting, blending, and manipulating sounds in words
* learning the names of letters and their associated sounds
* phonological memory
* rapid naming of familiar objects, colors, or letters of the alphabet
Secondary consequences of dyslexia may include the following:
* variable difficulty with aspects of reading comprehension
* variable difficulty with aspects of written composition
* a limited amount of time spent in reading activities.