Assessment and Diagnosis of Dyslexia

An assessment may be required at any age for a number of reasons.

DTS is able to provide assessments for:

  • Primary school students needing to build their literacy skills.

  • Secondary school students struggling with literacy and assignments.

  • Secondary and tertiary students who struggle with reading and writing.

  • Adults in the workforce and/or studying or training.

  • All ages for reasonable adjustments to school or employment tasks - ASK how we may best help you.


What is dyslexia?

Dyslexia is often referred to as a language based learning disability. It is the most common form of learning disability. Approximately 16% of the population has a learning disability and Individuals with dyslexia usually have difficulty with receptive oral language skills, expressive oral language skills, reading, spelling, or written expression.

Dyslexia varies in degrees of severity. The prognosis depends on the severity of the disability, specific patterns of strengths and weaknesses with the individual, and the appropriateness of the intervention. It is not a result of lack of motivation, sensory impairment, inadequate instruction, environmental opportunities, low intelligence, or other limiting conditions. It is a condition, which is neurologically based and often appears in families. Individuals with dyslexia respond successfully to timely and appropriate intervention.

Why is an evaluation important?

If you suspect dyslexia, it is important to have an evaluation to better understand the problem. Test results determine eligibility for special education support in various states, and they also determine eligibility for programs in colleges and universities. They provide a basis for making educational recommendations and determine the baseline from which remediation programs will be evaluated.

At what age should an individual be tested for dyslexia?

Individuals may be tested for dyslexia at any age. Tests, which are selected, will vary according to the age of the individual. Young children may be tested for phonological processing, receptive and expressive language abilities, and the ability to make sound/symbol associations. When problems are found in these areas remediation can begin immediately. A diagnosis of dyslexia need not be made in order to offer early intervention in reading instruction.

Who is qualified to make the diagnosis of dyslexia?

Professionals who possess expertise in several disciplines are best qualified to make a diagnosis of dyslexia. The testing may be done by a single individual or by a team of specialists. A knowledge and background in psychology, reading, language and education is necessary. The tester must have knowledge of how individuals learn to read and why some people have trouble learning to read, and must also understand how to measure appropriate reading interventions is necessary to make recommendations.

What test is used to identify dyslexia?

There is no one single test, which can be used to test for dyslexia. A battery of tests must be administered. Tests should be chosen on the basis of their measurement properties and their potential to address referral issues. Various tests may be used but the components of a good assessment should remain constant. Tests, which measure expressive oral language, expressive written language, receptive oral language, receptive written language, intellectual functioning, cognitive processing, and educational achievement must be administered.

What should an evaluation include?

The expert evaluator will conduct a comprehensive assessment to determine whether the person's learning problems may be related to other disorders. Attention deficit hyperactivity disorder (ADHD), affective disorders (anxiety, depression), central auditory processing dysfunction, pervasive developmental disorders, and physical or sensory impairments are among the other causes of learning problems that a competent evaluator will consider in making the diagnosis of dyslexia.

The following elements should be included in an assessment for dyslexia:

1. a developmental, medical, behavioural, academic and family history,

2. a measure of general intellectual functioning

3. information on cognitive processing (language, memory, auditory processing, visual processing, visual motor integration, reasoning abilities, and executive functioning),

4. tests of specific oral language skills related to reading and writing success to include tests of phonological processing,

5. educational tests to determine level of functioning in basic skill areas of reading, spelling, written language, and math -- testing in reading/writing should include the following measures:

* single word decoding of both real and nonsense words,

* oral reading in context (evaluate rate, fluency, comprehension and accuracy),

* reading comprehension,

* dictated spelling test,

* written expression: sentence writing as well as story or essay writing,

* handwriting,

What happens after the evaluation?

Discuss the test results with the individual who did the testing. You should receive a written report consisting of both the test scores as well as an explanation of the results of the testing. Administered tests should be specified. The strengths and weaknesses of the individual should be explained and specific recommendations should be made.

In the case of school-aged students, when there is a reading problem, the report should suggest recommendations for specific intervention techniques. This instruction should be provided by skilled teachers, specifically trained in structured language, multisensory programs.

Dyslexic adults should receive specific suggestions for management strategies and remediation. Additional help to implement these strategies and recommendations can also be considered. If the testing was done in connection with a current professional problem, the report should include specific suggestions for modifications and accommodations related to job performance.

How long does testing take?

An average assessment will take about 90 minutes. The extent of the evaluation is based on clinical judgment.

Adapted for Australian settings from an International Dyslexia Association document.