Testing for Learning Disabilities

Psychological testing is crucial for the diagnosis of learning disability. A learning disability is diagnosed when a specific ability, such as reading, is significantly lower than a person’s general ability, usually measured by an IQ test. Specific abilities can be measured with academic achievement tests such as the Woodcock-Johnson-III or WRAT-4.

The DSM-5 (psychiatric diagnostic manual) lists Specific Learning Disorders with impairment in:

Reading: Reading skills are weaker than general ability. Can included ability to decode words and/or reading comprehension. Another term for reading or writing disorders is Dyslexia.
Written Expression: Writing skills are weaker than general ability. Can include the quality of written expression, spelling, writing speed and legibility, and/or writing syntax.
Mathematics: Calculation skills are weaker than general ability.
Learning Disorder, Not Otherwise Specified: Can be diagnosed when there is a mild deficit in two or three of the areas listed above (reading, writing, and math) that individually fall short of diagnostic criteria, but together can be considered as a significant impairment.
Other Learning Disorders: Other disorders are often diagnosed in educational settings, but are not listed in the DSM-5. These include Auditory Processing Disorder (verbal skills weaker than nonverbal) or Visual Processing Disorder (spatial skills weaker than verbal).

Testing can also be used to diagnose or rule out attention deficit disorders. A continuous performance test, performance on certain IQ subtests, and teacher and/or parent reports can be combined to make a definitive and accurate diagnosis.