Diagnostic Tests for Dyslexia
A Multi-Approach to Diagnosis
Diagnosis is the single most important test before treating any kind of illness. But diagnosis and treatment do not always exist together. On one hand, there might be a way to correctly and easily diagnose a condition but there is no treatment that will address the medical problem. On the other hand, there is no easy method to diagnosis but there is an existing effective treatment. In the case of dyslexia, the affected children could neither have effective treatment nor easy diagnosis.
Treatment for dyslexia does not address the neurological problems that caused the reading difficulties. The focus of treatment is on the accommodation of the learning problem. That is, the teaching methods and the classroom environment are modified so that the dyslexic child may overcome his/her reading challenges. The prognosis is generally positive for those who had early interventions, but the severity of the symptoms can significantly affect the effectiveness of the treatment.
Before any treatment is even considered, there should be a correct diagnosis. Unfortunately, testing for dyslexia is difficult because there is no single assessment tool that will identify dyslexic children. Observations such as skipped words and lines while reading and an inability to count backwards are not sufficient. Such observations might be due to other learning disabilities and not dyslexia.
To rule out other learning disabilities and to be certain about the existence of dyslexia, school psychologists and other professionals in the field of special education end up utilizing several diagnostic tests. It is not inconceivable to have a child undergo a dozen tests before he/she will be diagnosed with dyslexia. This multi-approach to diagnosing dyslexia, so far, is the method that is currently used.
The Assessment Tests
Although several tests are utilized in diagnosing dyslexia, it is not advisable to assume that any assessment test will be useful. In fact, assessment tests are carefully chosen so that the reading difficulties are correctly analyzed. And the first tests that are utilized are intelligence tests, which will compare the child’s functional reading level and his/her reading potential.
When a disparity is observed, that is, the functional reading level is considerably lower than the reading potential, further testing is needed. The next group of tests will attempt to pinpoint the phase where the reading process collapsed. And then, another group of tests will be used to analyze how a child receives, perceives, conceptualizes, and processes information.
Specifically, the battery of tests should reveal how his/her sensory systems or modalities function independently and with each other. The psychologist would want to know if the child’s perceives information better through the eyes or through the ears. The psychologist would also want to know if the child is more adept at receiving than at providing information. The following are some of the assessment tests that are currently utilized:
- Beery Developmental Test of Visual-Motor Integration
- Bender Gestalt Test of Visual Motor Perception
- Expressive One-Word Picture Vocabulary Test
- KABC - Kaufman Assessment Battery for Children
- KTEA - Kaufman Tests of Educational Achievement
- Motor-Free Visual Perception Test
- PIAT - Peabody Individual Achievement Tests-Revised
- Peabody Picture Vocabulary Test-Revised
- Stanford-Binet Intelligence Scale
- TACL - Test for Auditory Comprehension of Language
- TAPS - Test of Auditory Perception (TAPS)
- TVPS - Test of Visual Perception (TVPS)
- VADS - Visual Aural Digit Span Test (VADS)
- WIAT - Wechsler Individual Achievement Tests (WIAT)
- WISC-III - Wechsler Intelligence Scale for Children-Third Edition (WISC-III)
- Woodcock-Johnson Psycho-Educational Battery