Dyslexia, Dyslexia Testing & Diagnosis

Dyslexia Tests

I was asked the other day by friend ‘How do you test if someone has dyslexia?’. My first answer was to send them to an educational psychologist. After my friend explained they wanted to know what actually happened in the test I was forced to think hard. I’ve been tested for dyslexia at least three times but I could remember very little of what actually took place. So I struggled to give a straight answer. Now, having looked into it, I’m still not sure I can give a straight answer.

The first problem is that dyslexia has no formal definition. Unlike ADHD, there is no definition in the DSM-IV, the psychologist diagnostic bible. Amongst academics it is generally accept to mean a problem with reading and writing that has no obvious cause, e.g. bad eyesight. Outside academia, dyslexia is seen as a wider problem, involving poor short-term memory and motor skills (clumsiness).

When talking about dyslexia tests we must separate dyslexia screening tests from dyslexia diagnostic tests. A screening tests is designed to quick and easy to administer. Its purpose is to weed out people who aren’t dyslexic. Anyone the screening test identifies as a potentially dyslexic can then go on to full diagnostic test. This prevents time and money being wasted on full tests for people who are clearly not dyslexic. All dyslexia tests on the internet or automated tests like the Lucid Dyslexia Screening Test will only screen out people who are not dyslexic.

A full test to diagnose dyslexia requires an educational psychologist or similar to administer it. These are expensive, often several hundred pounds, though organisation such as the British Dyslexia Association can help with the cost.

Not surprisingly a reading test is an integral part of a dyslexia diagnosis. In the early days of dyslexia it was believed that reading difficulties were related to intelligence. So an IQ test would be administered followed by a reading test. If the individual’s reading level was significantly below that expect for their intelligence, then the person was dyslexic. Our current understanding is that intelligence has very little to do with reading ability. Educationally sub-normal people can learn the mechanic of reading just as well as people with normal levels of IQ.

Memory tests are often used in dyslexia diagnosis. This often takes the form of a Reverse Auditory Digit Span. In this the tester will read out between a string of digits, such as Four Six Two, and testee has to repeat the digits backwards, e.g. Two Six Four. An average adult should be able to cope with five or six digits before making mistakes where as a dyslexic might only manage two digits.

Spelling and handwriting will often be assessed by asking the participant to write a short essay. How much the student writes in the time allowed as well the level of spelling mistakes will be noted. Dyslexics are normally slower writers than children of the same age.

There is no single dyslexia test and details will vary between education psychologists, schools and countries. If you are parent thinking of having your child testing for dyslexia make sure you know what is being tested and you understand what the results mean. A good test will not tell you whether they are dyslexic or not but also what their current level of abilities are. This gives you a base line against that you can measure future progress against.

Sources: Defining Dyslexia: A Modern Dilemma; The National Academy for Child Development (NACD)


  1. Chris, it never fails to astonish me that the English speaking countries do not have a common definition of dyslexia and do not have a uniform approach for remediation and accomodation.

    Your readers may be interested to read this page from Wrightslaw: http://www.wrightslaw.com/advoc/articles/tests_measurementspf.html

    Tests and Measurements for Parents, Advocates and Attorneys.

    From SchwabLearning:

    What’s Involved in Psychoeducational Assessments

    and http://www.schwablearning.org/articles.asp?r=864

    Understanding the Results of Psychoeducational Assessments.

    In http://www.ldonline.org/article/6026

    article from LDOnline,

    “In an issue of The International (Orton) Dyslexia Society’s newsletter Perspectives, Dr. Jane Fell Greene was asked about the proper tests to use with dyslexic and learning disabled children.

    Dyslexia is difficulty with language. Dyslexics experience problems in psycholinguistic processing. They have difficulty translating language to thought (reading or listening), or thought to language (writing or speaking). Although psychological, behavioral, emotional or social problems may result from dyslexia, they do not cause dyslexia. One test is inadequate: a battery is required. Typical psychoeducational tests were not designed to identify dyslexia.

    Dr. Greene recommended using the
    Detroit Tests of Learning Aptitude

    as a global test that primarily tests verbal and non verbal language. “It measures the level at which the individual would perform if appropriate interventions were implemented (as is required by federal law).”

    The article recommended additional tests by age group.

    The tests for preschool and kindergarten were the

    Test of Phonological Awareness,
    Tests of Early Written Language,
    Test of Early Reading Ability, and the

    Preschool Evaluation Scale.

    For primary years, the following were recommended –

    Test of Phonological Awareness,
    Test of Language Development,
    Peabody Individual Achievement Tests,
    Gray Oral Reading Test,
    PIAT Test of Written Expression, and the
    Wide Range Achievement Test.

    For elementary students Dr. Greene recommended the

    Test of Language Development, the Peabody Individual Achievement Test,
    Gray Oral Reading Test,
    PIAT Test of Written Expression and the

    Wide Range Achievement Test.

    For the adolescent and adult she recommended the
    Test of Adolescent and Adult Language,

    the Peabody Individual Achievement Test,

    the Gray Oral Reading Test, the PIAT Test of Written Expression and the

    Wide Range Achievement Test.

    The Detroit was recommended for all age levels. “

  2. You are also mistaken about the DSM-IV. The code is 315.00 and the title is Developmental REading Disorder. 315.1 is Developmental Math Disorder; 315.2 is Disorder of Written Expression; 315.39 is Phonological Disorder.

    In addition, in the United States, most students wanting accomodations on standardized tests must have a battery of tests that include:

    ssessment: For the neurological or psychological evaluation to illustrate a substantial limitation to learning, the comprehensive assessment battery must contain the following domains:

    1. Aptitude/Cognitive Ability: An assessment of global intellectual functioning as measured by the Wechsler Adult Intelligence Scale-III (WAIS-III) with all subtests, standard scores, and index scores.
    2. Academic Achievement: A comprehensive achievement battery (e.g., Woodcock-Johnson Psychoeducational Battery – III: Tests of Achievement) with subtest and standard scores, indicating current level of functioning in the academic areas of reading, math, oral and written language.
    3. Information Processing: A comprehensive battery (e.g. Woodcock-Johnson Psychoeducational Battery – III: Tests of Cognitive Abilities) with subtest and standard scores which addresses the specific areas of short and long-term memory, sequential memory, auditory and visual perception, processing speed, executive functioning, and motor ability.

  3. ann

    However Chris ,

    Those do not test for dyslexia those test do not test specifically for dislexia. Because there is no norm referenced test that can say yes you are dyslexic. Those test address Learning disablitites in which some believe is what dyslexia is and is an eductional problem in which through remediation it is “cured” or overcomed. In most cases it is the medical profession who uses the term dyslexia to describe a group of characteristics found in a indivuales that have marked differences in thier brain processing of lanugue that becomes a problem because of the waywe teach one way. That is considered a life long problem that through supportive techniues a person can achieve thier true potentional. Some professional belive that MRI and EEG with provide us with information and thiere has been much progress in this area. However, not everyone with this disirder at this time comes up with a postive result. I find this information inportant to put ou because there are to nmany myths out there about this disorder. Yes am a sever dyslexic . My mother sent me to 20 programs to cue me. Yes im still dyslexic and the biggest problems are the myths. Thanks for listening.

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