What to Expect from a Psychological Evaluation
By Jolynn-Marie Wagner, Ph.D.
The role of the psychologist in any type of psychological testing is to be an objective and unbiased evaluator. For this reason, an evaluating psychologist cannot be that client’s therapist nor have any other type of relationship with the client that may impair his or her objectivity. While a treating psychologist may do some testing in order to gain more knowledge about a client to better design a treatment plan, treating psychologists generally do not undertake full evaluations of their therapy clients.
The purpose of the testing and evaluation is dependent on the referral questions. Most frequently, evaluations are conducted to determine a client’s overall level of psychological functioning or to make or rule out a specific diagnosis. The types of diagnoses that are evaluated may include: learning or developmental disorders, attentional disorders, cognitive impairments, mental disorders such as depression, anxiety, post traumatic stress disorder, personality disorders, etc. Use of normed tests, such as an IQ test or a normed personality test, give the evaluator information about how the client performs on a particular test compared to age, and sometimes gender peers. However, an evaluator also gathers information from other sources who know the client, from the client herself, and evaluates based on clinical experience.
There are numerous types of tests and measures that psychologists use to conduct evaluations. However, the different tests can be broken down into general categories by types of skill or ability the tests are meant to measure. These categories would include: tests that measure broad, cognitive abilities (intelligence tests and similar cognitive test batteries), tests of academic achievement, tests of specific language skill, tests of motor skill, tests of visual-perceptual skill, tests of social-emotional skill and personality testing, tests of adaptive behavior, and tests of specific brain functioning, or neuropsychological functioning. Most evaluation with include an IQ and academic achievement test, and other tests used depend on the referral question. With adolescents and adults, personality tests are often also used.
Another type of measure that is typically used with children are checklists. Parents, teachers, and/or daycare providers are often asked to complete behavioral checklists in order to provide information about the child to the psychologist. Children 11 years old and older often complete their own checklist as well.
Psychological assessment is not limited to use of formal tests by the psychologist, and a client’s scores on psychological tests must be interpreted within the context of the client’s history and current situation. For this reason, evaluations also include interviews with the client and parent (if the client is a child), structured and unstructured observations of the client, observation of parent-child interaction, and questionnaires and rating scales completed by the client and/or parent, teachers, and caregivers.
Common Names and Frames: As in any area, there are common names and "lingo" used in the testing field. Most commonly used IQ tests are the Wechsler series, which includes the WPPSI (Wechsler Preschool and Primary Scale of Intelligence), WISC (Wechsler Intelligence Scale for Children), and the WAIS (Wechsler Adult Intelligence Scale). Used less often, you may hear of the Stanford-Binet or the Bayler Scales. If you or your child takes an academic achievement test, you may hear about the WIAT (Wechsler Individual Achievement Test), the WRAT (Wide range Achievement test), or the Woodcock-Johnson. All three are commonly used to measure academic achievement.
When talking about testing, you may hear a psychologist mention norms, the mean, standard deviation, or significant differences between scores. When a test is normed, it means that a large study sample took the test and the test developer calculated the norms for the test, including the mean, or average, and the standard deviation, or how much variability in scores occurred within the test sample. For example, on the Wechsler series IQ test, the mean is 100 and the standard deviation is 15. That means that while most people tend to score about 100 on the test, scores from 85 to 115 are within one standard deviation, or within normal limits. When a psychologist talks about a test scores being "statistically different," they mean that the difference in scores are more likely caused by true differences in the individual’s abilities than by chance.
The specific scores that a client receives are only a sample of the client’s skill or behavior that is part of a wider range of skills and behaviors that the client actually possesses. Test scores are also dependent on the client’s motivation and cooperation. Further, a client may score differently on a different test or with a different examiner due to differences in tests and/or examiners, or fluctuations in conditions such as environment, fatigue, or stress. Finally, specific diagnosis cannot be guaranteed and sometimes no diagnosis is made. Often, the client is being evaluated to rule out a specific problem or diagnosis.
Feedback is given to the client and/or parents verbally after the evaluation is completed. Feedback sessions should include the evaluator’s impressions, how he/she reached that impression, and the evaluator’s recommendations for the client, such as certain treatments or referrals. Feedback can also be provided in a written report if desired by the client. Depending on the purpose of the report, the length of the report will vary and specific test scores may or may not be included in the test.