Intelligence quotient (IQ) tests are used to measure intellectual potential. The three tests most widely used include the Wechsler Intelligence Scale for Children (WISC), the Standford-Binet Intelligence Test, and the Kaufman-Assessment Battery for Children (K-ABC).

IQ tests must be administered by psychologists or other professionals who have been licensed by the state to conduct such testing. Special education teachers, unless specifically licensed to do so, may not administer these tests. The purpose of IQ tests is to obtain global estimates of a student’s intellectual ability. An IQ test may not be the sole criterion on which a student’s disability is determined, and the results of the test should not be the sole basis used to determine services under the Individuals with Disabilities Education Act.

In addition to the IQ tests mentioned above, the Kaufman brief intelligence test (K-BIT) is used by some evaluators. However, this test is a shorter version and as a result should not be used to make educational decisions that will affect a child’s long-term educational needs.

Evaluators often use the Test of Nonverbal Intelligence to obtain an IQ score for children with communication challenges. The test is administered entirely free of the use of language and requires no reading, writing, or speaking. By using this test, the evaluator is not testing to the weakness of the child, as all previous mentioned IQ tests require that the child have adequate verbal abilities to answer the questions presented.

In addition to considering the challenges of testing to a child’s weakness, evaluators are becoming more and more aware that IQ tests often have an innate bias in measuring the IQ of minority groups. Tests to minimize multicultural bias are now more widely used than before.

Development of IQ tests is time consuming and expensive. IQ tests, as well as other standardized tests, must be validated for the specific purpose for which they are used. For example, a test that is designed to evaluate phonic abilities is not valid for testing simple reading abilities. Moreover, test scores must be determined to be reliable in that the test scores are consistent. If given an IQ test repeatedly, the student’s scores should be the same or within a standard error of measurement each time it is administered.

All standardized IQ tests are normed against a group chosen to provide a basis of comparison of the students taking the IQ test. Therefore, if the WISC is normed against 6 to 16 year old hearing students, such a test would not be appropriate to use with 6 to 16 year old nonhearing students.

Remember that IQ tests are simply estimates. An IQ test is just an estimate of a child’s ability on one particular day.