Dyslexia is one of several different kinds of learning disabilities, and it is the most common one, comprising about 85 percent of people who have a learning disability. This was described about in the Learning Disability/Dyslexia Testing section. There is some more information about dyslexia below.
There is a narrow definition and a broad definition of dyslexia. I will discuss both levels of this term in dealing with dyslexia testing.
The narrow view of dyslexia is that it has to do with problems in phonological processing, or the connecting of the visual symbol (the word on the page) to the sound of the word (what you speak and hear). Therefore, dyslexia testing usually involve giving someone tests of different aspects of phonological processing. If scores on these tests are much lower than the person's overall level of mental ability (usually thought to be the Intelligence Quotient or IQ), then the person would be noted as having a phonological processing problem. If the person also had a problem in slow reading, or does not have adequate reading comprehension, then the diagnosis of dyslexia would be very reasonable. Thus, dyslexia testing would involved giving the person several tests involving the underlying cognitive processes of dyslexia and comparing these with the person's overall mental or intellectual ability.
Additionally, there might be other processing problems that should be assessed in dyslexia testing besides the principle one noted above, phonological processing. Some people might have a problem in remembering the sound/symbol relationship of the word patterns they see in reading. Or they might have a problem in speeded visual processing, but their phonological processing might be just fine. Another person might have a problem in getting things in the right order, which is a sequencing problem. There could be a variety of processing problems a person has, and different people can have different combinations of problems, some worse than others. That is what makes it hard to say what dyslexia is: It can be a variety of processing problems. Therefore, if dyslexia testing is to be comprehensive, it should cover most of the different variations of processing problems.
There are some other qualifying issues with regard to diagnosing dyslexia, however. The problem of dyslexia, or someone with slow reading, must not be due to the person having a sensory problem (such as bad eyesight), and they must have had the opportunity to learn to read. Therefore, if a person was not in school or somehow did not have the opportunity to learn to read the way other children did, he/she could not be considered dyslexic until the chance to learn was provided. In other words, professionals in the field are interested in distinguishing the relevant factors which may be contributing to a person's problems with reading. Dyslexia should be associated with cognitive (or mental) processing problems, not with problems in having the proper educational opportunities.
There are many tests to consider in dyslexia testing. First, one needs to assess the overall intelligence in order to get the general level of ability in the person, usually using the Wechsler Intelligence Scale for Children (6 to 16 years of age) or the Wechsler Adult Intelligence Scale (from 16 years on). Then the psychologist testing for dyslexia gives tests which measure other aspects of mental functioning, including phonological processing, visual speeded processing, verbal and visual memory, speeded language processing of various kinds, visual-motor integration, abstract reasoning (visual and verbal), naming and other cognitive functions. Some common batteries are the Woodcock-Johnson Battery-III, the Nelson-Denny Reading Test and the Wechsler Individual Achievement Test-II. Usually these tests will show what the specific problems are for the person being tested.
The testing often takes about 8 hours of time with a person who is testing for dyslexia. Sometimes it can be shorter, but usually no less than 5 hours. Sometimes it will be longer if there is a reason to assess other cognitive functions; this is sometimes necessary when a person is requesting extra time on a standardized test, such as the SAT, GRE, MCAT or LSAT. I have even tested people to get extra time for the surgery boards! Yes, a person can be very smart and have dyslexia!
A full evaluation for dyslexia takes about 8 hours of testing and 6-7 hours to write the report. Please visit our contact page to learn how to schedule testing.
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