Psychological testing is a field characterized by the use of samples of behavior in order to infer generalizations about a given individual. The technical term for the science behind psychological testing is psychometrics. By samples of behavior, one means observations over time of an individual performing tasks that have usually been prescribed beforehand, which often means scores on a test. These responses are often compiled into statistical tables that allow the evaluator to compare the behavior of the individual being tested to the responses of a norm group.
Psychological testing is not the same as psychological assessment. Psychological assessment is a process that involves the integration of information from multiple sources, such as psychological tests, and other information such as personal and medical history, description of current symptoms and problems by either self or others, and collateral information (interviews with other persons about the person being assessed). A psychological test is one of the sources of data used within the process of assessment; usually more than one test is used. All psychologists do some level of assessment when providing services to clients or patients, and may use for example, simple checklists to assess some traits or symptoms, but psychological assessment is a more complex, detailed, in-depth process. Typical types of focus for psychological assessment are to provided a diagnosis, assess level of function or disability, help direct treatment, and assess treatment outcome.
Types of Psychological Tests
IQ/achievement tests IQ tests are measures of intelligence, while achievement tests are measures of the use and level of development of use of the ability. IQ (or cognitive) tests and achievement tests are common norm-referenced tests. In these types of tests, a series of tasks is presented to the person being evaluated, and the person's responses are graded according to carefully prescribed guidelines. After the test is completed, the results can be compiled and compared to the responses of a norm group, usually comprised of people at the same age or grade level as the person being evaluated. IQ tests which contain a series of tasks typically divide the tasks into verbal (relying on the use of language) and performance, or non-verbal (relying on eye-hand types of tasks, or use of symbols or objects). Examples of verbal IQ test tasks are vocabulary and information (answering general knowledge questions). Non-verbal examples are timed completion of puzzles (object assembly), making designs out of coloured blocks (block design).
IQ tests (e.g., WAIS-III, WISC-IV, Cattell Culture Fair III and academic achievement tests (e.g., WIAT, WRAT) are designed to be administered to either an individual (by a trained evaluator) or to a group of people (paper and pencil tests). The individually-administered tests tend to be more comprehensive, more reliable, more valid and generally to have better psychometric characteristics than group-administered tests. However, individually-administered tests are more expensive to administer because of the need for a trained administrator (psychologist, school psychologist, or psychometrician) and because of the limitation of working with just one client at a time.
Neuropsychological tests
These tests consist of specifically designed tasks used to measure a psychological function known to be linked to a particular brain structure or pathway. They are typically used to assess impairment after an injury or illness known to affect neurocognitive functioning, or when used in research, to contrast neuropsychological abilities across experimental groups.
Personality tests
Psychological measures of personality are often described as either objective tests or projective tests. Some projective tests are used less often today because they are more time consuming to administer.Objective tests (Rating scale)
Objective tests have a restricted response format, such as allowing for true or false answers or rating using an ordinal scale. Prominent examples of objective personality tests include the Minnesota Multiphasic Personality Inventory, Millon Clinical Multiaxial Inventory-III, Child Behavior Checklist, and the Beck Depression Inventory. Objective personality tests can be designed for use in business for potential employees, such as the NEO-PI, the 16PF, and the Occupational Personality questionnaire, all of which are based on the Big Five taxonomy. The Big Five, or Five Factor Model of normal personality, has gained acceptance since the early 1990s when some influential meta-analyses (e.g., Barrick & Mount 1991) found consistent relationships between the Big Five personality factors and important criterion variables.
Projective tests (Free response measures)
Projective tests allow for a freer type of response. An example of this would be the Rorschach test, in which a person states what each of ten ink blots might be. The terms "objective test" and "projective test" have recently come under criticism in the Journal of Personality Assessment. The more descriptive "rating scale or self-report measures" and "free response measures" are suggested, rather than the terms "objective tests" and "projective tests," respectively.
As improved sampling and statistical methods developed, much controversy regarding the utility and validity of projective testing has occurred. The use of clinical judgement rather than norms and statistics to evaluate people's characteristics has convinced many that projetives are deficient and unreliable (results are too dissimilar each time a test is given to the same person). However, many practitioners continue to rely on projective testing, and some testing experts (e.g., Cohen, Anastasi) suggest that these measures can be useful in developing therapeutic rapport. They may also be useful in creating inferences to follow-up with other methods. Possibly they have lingered in usage because they have a mystical and fascinating reputation, and are more attractive to uninformed people than answering objective tests, e.g., true/false questionnaires. The most widely used scoring system for the Rorschach is the Exner system of scoring. Another common projective test is the Thematic Apperception Test (TAT), which is often scored with Westen's Social Cognition and Object Relations Scales and Phebe Cramer's Defense Mechanisms Manual. Both "rating scale" and "free response" measures are used in contemporary clinical practice, with a trend toward the former.
Sexological testsThe number of tests specifically meant for the field of sexology is quite limited. The field of sexology provides different psychological evaluation devices in order to examine the various aspects of the discomfort, problem or dysfunction, regardless of whether they are individual or relational ones.
Direct observation tests
Although most psychological tests are "rating scale" or "free response" measures, psychological assessment may also involve the observation of people as they complete activities. This type of assessment is usually conducted with families in a laboratory, home or with children in a classroom. The purpose may be clinical, such as to establish a pre-intervention baseline of a child's hyperactive or aggressive classroom behaviors or to observe the nature of a parent-child interaction in order to understand a relational disorder. Direct observation procedures are also used in research, for example to study the relationship between intrapsychic variables and specific target behaviors, or to explore sequences of behavioral interaction. The Parent-Child Interaction Assessment-II (PCIA) is an example of a direct observation procedure that is used with school-age children and parents. The parents and children are video recorded playing at a make-believe zoo. The Parent-Child Early Relational Assessment (Clark, 1999) is used to study parents and young children and involves a feeding and a puzzle task. The MacArthur Story Stem Battery (MSSB) is used to elicit narratives from children. The Dyadic Parent-Child Interaction Coding System-II (Eyberg, 1981) tracks the extent to which children follow the commands of parents and vice versa and is well suited to the study of children with Oppositional Defiant Disorders and their parents.