Assessment for special education is foundational for the success of identification, placement, and programming for children with special needs. Assessment can range from the formal--standardized, to the informal:--teacher-made assessments. This article will cover formal instruments for measuring students' intelligence, achievement (or academic ability) and function.
Testing to Assess Whole Districts or Populations
Standardized testing is any testing which is given to large numbers of students under standard conditions and with standardized procedures. Usually, they are multiple choice. Today many schools administer a standardized achievement test to prepare for their state's annual NCLB assessment. Examples of a standardized achievement tests include the California Achievement Test (CAT); Comprehensive Test of Basic Skills (CTBS), which includes the "Terra Nova"; Iowa Test of Basic Skills (ITBS) and Tests of Academic Proficiency (TAP); Metropolitan Achievement Test (MAT); and Stanford Achievement Test (SAT.)
These tests are normed, which means the results are compared across ages and grades statistically so that a mean (average) for each grade and age are created which are the Grade Equivalent and Age Equivalent scores that are assigned to individuals. A GE (Grade Equivalent) score of 3.2 represents how a typical third-grade student in the second month performed on the previous year's test.
State or High Stakes Testing
Another form of standardized testing is the state assessment required by No Child Left Behind (NCLB). These are usually administered during a strictly regimented window in late winter. Federal law only permits 3% of all students to be exempted because of disabilities, and these students are required to take an alternate assessment, which can be simple; or dizzyingly convoluted.
Individual Tests for Identification
Individualized intelligence tests are usually part of the battery of tests a school psychologist will use to evaluate students when referred for evaluation. The two most commonly used are the WISC (Wechsler Intelligence Scale for Children) and the Stanford-Binet. For many years the WISC has been considered the most valid measure of intelligence because it had both language and symbol based items and performance-based items. The WISC also provided diagnostic information, because the verbal part of the test could be compared to the performance items, to show a disparity between language and spatial intelligence.
The Stanford-Binet Intelligence Scale, originally the Binet-Simon Test, was designed to identify students with cognitive disabilities. The scales focus on language narrowed the definition of intelligence, which has been to some extent broadened in the most recent form, the SB5. Both the Stanford-Binet and WISC are normed, comparing samples from each age group.
Individualized achievement tests are useful for assessing a student's academic abilities. They are designed to measure both pre-academic and academic behavior: from the ability to match pictures and letters to more advanced literacy and mathematical skills. They can be helpful in assessing needs.
The Peabody Individual Achievement Test (PIAT) is an achievement test which is administered individually to students. Using a flip book and a record sheet, it is easily administered and requires little time. The results can be very helpful in identifying strengths and weaknesses. The PIAT is a criterion based test, which is also normed. It provides age equivalent and grade equivalent scores.
The Woodcock-Johnson Test of Achievement is another individualized test which measures academic areas and is appropriate for children from the ages of 4 to young adults to 20 and a half. The tester finds a base of a designated number of consecutive correct answers and works to a ceiling of the same incorrect consecutive answers. The highest number correct, minus any incorrect responses, provide a standard score, which is quickly converted into a grade equivalent or age equivalent. The Woodcock-Johnson also provides diagnostic information as well as grade level performances on discrete literacy and mathematical skills, from letter recognition to mathematical fluency.
The Brigance Comprehensive Inventory of Basic Skills is another well-known, well-accepted criterion-based and normed individual achievement test. The Brigance provides diagnostic information on reading, math and other academic skills. As well as being one of the least expensive assessment instruments, the publisher provides software to help write IEP goals based on the assessments, called Goals and Objective Writers Software.
There are several tests of life and functional skills. Rather than reading and writing, these skills are more like eating and talking. The best known is the ABLLS (pronounced A-bels) or Assessment of Basic Language and Learning Skills. Designed as an instrument for assessing students specifically for Applied Behavioral Analysis and discrete trial training, it is an observational instrument that can be completed through an interview, indirect observation, or direct observation. You can purchase a kit with many of the items required for certain items, such as "naming 3 of 4 letters on letter cards." A time-consuming instrument, it is also meant to be cumulative, so a test book goes with a child from year to year as they acquire skills.
Another well known and reputable assessment is the Vineland Adaptive Behavior Scales, Second Edition. The Vineland is normed against a large population across ages. Its weakness is that it is comprised of parents' and teachers' surveys, which as indirect observations, have the weakness of being susceptible to subjective judgments. Still, when comparing language, social interaction and function at home with typically developing same-aged peers, the Vineland provides the special educator with a view of what the student's social, functional and pre-academic needs are.