Learning Disorders Diagnosis
Tests are used to compare children's performance relative to their peers, profile individual strengths and/or weaknesses, and to determine children's need for intervention. Other information, such as interviews with family members and teachers, behavioral observation of the child, and reviewing children's medical, social, and educational history is necessary to make an accurate diagnosis.
In the United States, parents typically have the right to request a learning disabilities evaluation for their child that is paid for by their relevant (public) school district. The most widely used model schools use to test for the presence of a learning disability is called the "discrepancy model". Under the discrepancy model, children receive separate IQ and academic achievement testing. The IQ test measures intellectual potential, while the achievement test measures actual performance and skill development. If all is going well developmentally, these two tests should agree. However, if a discrepancy exists between the results of the two evaluations, particularly if a child has a high IQ but performs poorly on the achievement tests, the child may have a learning disability.
If you believe that your child might suffer from a learning disorder and may benefit from a special education program, you should speak with your child's teachers and administrators so that they can help you obtain the best possible services for your child. The child should be tested by the School Psychologist or a private child psychologist for proper diagnosis. Some or all of the following tests may be used with your child:
Weschsler-Intelligence Scale for Children (WISC-IV)
The WISC-IV is an intelligence test designed for use with children between 6 and 16 years of age. The WISC consists of a combination of verbal (e.g., measuring language comprehension) and performance (e.g., assessing speed on problem solving tasks such as putting together puzzles or recreating patterns with blocks) tasks. This test provides an IQ score (quotient), that allows a clinician to compare the child's performance to other children his or her age. An average IQ score is 100. A different version of this test (the WPSSI) can be used with preschoolers.
The Woodcock-Johnson III is designed to measure general intellectual ability, specific cognitive abilities, scholastic aptitude, oral language, and academic achievement. This test is designed for use with individuals ages 2 to 90. This test can help pinpoint students' areas of strength and weaknesses, their learning style, and their aptitude in specific academic areas.
Wechsler Individual Achievement Test (WIAT)
The WIAT is an academic achievement test designed by the maker of the Wechsler IQ tests. Testers can easily make comparisons between the WIAT and Wechsler IQ scales, which allows for the determination of discrepancies (e.g., a child who scores high on achievement but very low on the IQ test) and, therefore, the presence of learning disabilities. WIAT test scores can be used to compare a child's current achievement level with what is expected for his or her grade level or age group.
Wide Range Achievement Test (WRAT)
The WRAT is designed to measure reading recognition, spelling, and math computation. There are two versions of the instrument, one for ages 5 through 11, and the other for ages 12 and over. This test may not be the best choice for children from minority groups, because normative comparison groups (to which children's scores are compared) probably did not accurately represent these children. Despite its limitations with particular populations, the WRAT can be used to compare one person to another with his or her age as a reference point, to determine learning abilities and disabilities, and to assess error patterns that could be helpful in planning specific instructional programs.