Formal assessment for dyslexia

Early assessment and identification of dyslexia (and early, effective intervention) are important.

When a child exhibits a number of signs of dyslexia, it is recommended that a thorough psycho-educational assessment be done by a qualified psychologist to identify the reason(s) for the reading, spelling and/or writing difficulty.

Who provides a psycho-educational assessment?

There are two ways to get a formal psycho-educational assessment

  1. Using a psychologist associated with your school board
  2. Using a private psychologist

Some private medical insurance policies will cover some of the costs of a psycho-educational assessment by a private psychologist if prescribed by a doctor.

What test is used to identify dyslexia?

There is no one test for dyslexia. The diagnosis of 'dyslexia' must be made by a psychologist.  A battery of tests must be administered, generally over two or three sessions. Individuals may be tested at any age. The psychologist may work with other professionals such as speech and language pathologists, physicians and occupational therapists.

What is 'specific learning disorder' and is it the same as 'dyslexia'?

Psychologists, teachers, clinicians, and researchers use different terms to describe reading problems, which can be very confusing.  In psycho-educational assessments, private psychologists often use the terms "specific learning disorder" or "specific learning disorder with impairment in reading, or writing", which is characterized as “one where people have difficulties with word reading accuracy, reading rate or fluency and reading comprehension” (from The Diagnostic and Statistical Manual of Mental Disorders (DSM-V), 5thEdition, 2013, The American Psychiatric Association).

Other equivalent terms are ‘specific learning disability’, ‘reading disability’, ‘decoding disability.’  These equivalent terms, including the term 'dyslexia', refer to the same condition of difficulty with word-level reading (decoding), spelling (encoding), and writing. The DSM-V stipulates that “dyslexia is an alternative term used to refer to a pattern of learning difficulties characterized by problems with accurate or fluent word recognition, poor decoding, and poor spelling abilities."

Ontario school board psychologists usually use the diagnostic term ‘learning disability’, based on the recommended practice guidelines from the Learning Disabilities Associations of Ontario & Canada (LDAO, 2001) and ratified in 2015 (LDAC, 2015)).  These guidelines do not use the term ‘dyslexia’ or ‘reading disability’, just ‘learning disability’.   The LDAC document (2015) provides a comparison of the LDAC learning disability definition and the DSM-5 Specific Learning Disorder definition.  Kozey & Siegel (2008) provide a summary of definitions of learning disability used in various provinces across Canada.

In 2018 the Ontario Psychological Association (OPA) released a new document “OPA Guidelines for Diagnosis and Assessment of Children, Adolescents, and Adults with Learning Disabilities” (OPA, 2018).  This document also uses the general term ‘learning disability’.

*NEW* In a March 2020 revision of the OPA document, FAQ #7 "What is dyslexia" was added (p. 37-39). The International Dyslexia Association's definition of dyslexia is provided and clarification that "When individuals meet the criteria for LD in the OPA Guidelines and have difficulties with word and pseudo-word reading and phonological or orthographic processing an additional diagnosis of dyslexia might be made."

The guidelines mention that "dyslexia (or word-level reading disabilities) is arguably the most highly researched type of LD including research on the neurological basis, genetic basis, assessment, and intervention (see Fletcher et al. 2019; Kilpatrick, 2015, for reviews). Between 3% and 7% of the population meet criteria for this diagnosis depending on the cut-off used for below-average achievement in word-level reading".

Regarding intervention, the OPA document says "Considerable research has pointed to the key components of intervention for dyslexia (Fletcher et al. 2019). There is considerable evidence that good Tier 1 literacy programs prevent reading problems in most children and reduce the number of children who would require an assessment and remedial interventions for reading disabilities. Early intervention has been found to be very important because remediation after the primary grades must be intense and fluency is reduced. Intervention should be done in the context of a reading program that includes recognition of common sight words, spelling, reading fluency, vocabulary, and reading comprehension. Explicit teaching of phonemic awareness, phonics, morphology, and units of orthography in reading and spelling is very important".


What should an evaluation include?

The psychologist will conduct a comprehensive assessment to determine whether the person’s learning problems may be related to other disorders, such as attention deficit and/or hyperactivity disorder, mood disorders, pervasive developmental disorders, and physical or sensory impairments.

In general, an evaluation will usually include the following:

  • A case history that includes information on developmental, medical, behaviour, academic,  family history and review of remediation efforts to date.
  • A measure of intellectual functioning (in Ontario, this is often the Wechsler Intelligence Scale for Children (WISC).
  • Tests of receptive (listening) and expressive (speaking) language skills.
  • Since dyslexia is often characterized by issues with phonological processing skills, the ability to rapidly name letters and objects and working memory it is helpful to include tests of these skills   (eg. Comprehensive Test of Phonological Processing which includes a test for Rapid Automatized Naming (RAN) and memory evaluations (eg. Wide Range Assessment of Memory and Learning, Second Edition (WRAML2)).
  • Educational tests to determine the level of functioning in basic skill areas of reading, spelling, written language and math. Testing in reading and writing should include the following measures: single word decoding of real and nonsense words, oral and silent reading in context, reading comprehension, spelling in isolation and in text, sentence, story and essay writing, handwriting.  Many psychologists in Ontario use The Wechsler Individual Achievement Test–Third Edition (WIAT-III).
  • Assessments for other issues such as behavioural assessment for Attention deficit hyperactivity disorder (ADHD).
  • Possibly a classroom observation.

If a profile emerges that is characteristic of dyslexia or a student is diagnosed with dyslexia, it is important to get effective Structured Literacy intervention and support for your child.