Dyslexia is a common disorder that affects up to 20% of the U.S. population. However, due to the complex nature of the learning disability, it is difficult to diagnose. To rule out other reading difficulties and deficits an evaluation should consist of a range of assessments. The following components should be part of a comprehensive evaluation for dyslexia.
Detailed History
It is important to understand a family’s history to determine if members have had educational struggles or reading-specific disabilities due to dyslexia showing a genetic component. The assessment should also collect information on attempted previous interventions and their level of success. Noting previous childhood trauma is also crucial, as dyslexia can be a response to challenges to the stress systems.
Decoding Ability
Children with dyslexia experience difficulty understanding how letters represent sounds. They frequently have trouble breaking new words down into smaller segments they can sound out, a process called decoding. Assessments should check for the following issues.
Phonemic Awareness
Central issues with dyslexia are difficulties perceiving and manipulating word sounds– comprehensive evaluation should consider phonemic awareness. Tests measuring this skill require examinees to identify or create rhymes, count phonemes, blend phonemes in pronouncing a word, and break words into syllables.
Orthographic Awareness
Orthographic mapping is the learning and recall of sounds that are associated with printed letters. Individuals with dyslexia can usually recognize individual letters with relative ease but have difficulty identifying letter patterns and complete words. Dyslexic subjects may:
- confuse similar letters and symbols
- struggle to read words that don’t follow regular spelling patterns
- drop the endings of words
- switch or reverse numbers and letters
- forget the spelling of words
- read slowly
Speed, Recall, and Fluency
Dyslexia can affect short-term memory, such as recent conversations, important dates, or tasks on a to-do list. It can also impact the ability to recall information, impacting processing speed and reading fluency. Speed and recall issues to be measured in a dyslexia assessment:
- Rapid Automatized Naming (RAN): measuring the ability to retrieve names of numbers, letters, and sight words
- Processing Speed: measuring auditory, perceptual, and motor speeds
- Memory: measuring word recognition, spelling, comprehension, and ability to summarize
- Word Reading: measuring reading (real and nonsense words) under timed and untimed conditions to demonstrate recognition and decoding skills and strategies
- Fluency: measuring the reading of passages or sentences to demonstrate sight word vocabulary, accuracy, expressiveness, rate, and speed
Other Reading Skills
A comprehensive dyslexia assessment goes beyond the basic skills to check an individual’s educational abilities in the following categories.
- Reading and Listening Comprehension: requires answering questions following a reading passage to measure the ability to understand the information read
- Oral Language: detects problems with receptive and expressive vocabulary, grammar, pragmatics, discourses, grammar, and phonological awareness
- Spelling and Writing: measures a student’s ability to spell accurately, including constructing words correctly and identifying incorrect spellings from a list
Learn more about comprehensive assessments, like Tests of Dyslexia (TOD™), and educational support for dyslexia and other learning disabilities at WPS.
