The law requires that the student be given an individually administered test of ability or intelligence and tests of achievement in areas such as reading, math, and writing. Some examples of intelligence or cognitive testing include: the Wechsler Intelligence Scale for Children, the Wechsler Pre-School and Primary Scale of Intelligence-Revised (WPPSI-R), the Stanford-Binet Intelligence Test, the Kaufman Assessment Battery for Children, and the Cognitive Assessment System.

The most commonly used achievement tests are the Wide Range Achievement Test (WRAT), the Peabody Individual Achievement Test (PIAT), and the Woodcock-Johnson Psycho Educational Battery-Revised (WJPEB-R). All of these are short tests designed to tell you the grade level and the age equivalency at which the student is performing in reading, writing, spelling, and math. 

The districts will also use clinical observations and informal interviews to gather data about daily living skills and functioning in the home and community.