Psychological testing refers to the administration of psychological tests. Psychological tests are administered or scored by trained evaluators. A person's responses are evaluated according to carefully prescribed guidelines. Scores are thought to reflect individual or group differences in the theoretical construct the test purports to measure. The science behind psychological testing is psychometrics.Nunnally, J.C., & Bernstein, I.H. (1994). Psychometric theory. New York: McGraw-Hill.
Psychological tests According to Anastasi and Urbina, psychological tests involve observations made on a "carefully chosen sample [emphasis authors] of an individual's behavior." A psychological test is often designed to measure unobserved constructs, also known as latent variables. Psychological tests can include a series of tasks, problems to solve, and characteristics (e.g., behaviors, symptoms) the presence of which the respondent affirms/denies to varying degrees. Psychological tests can include questionnaires and interviews. Questionnaire- and interview-based scales typically differ from psychoeducational tests, which ask for a respondent's maximum performance. Questionnaire- and interview-based scales, by contrast, ask for the respondent's typical behavior.Mellenbergh, G.J. (2008). Chapter 10: Surveys. In H.J. Adèr & G.J. Mellenbergh (Eds.) (with contributions by D.J. Hand), Advising on Research Methods: A consultant's companion (pp. 183-209). Huizen, The Netherlands: Johannes van Kessel Publishing. Symptom and attitude tests are more often called scales. A useful psychological test/scale must be both valid, i.e., show evidence that the test or scale measures what it is purported to measure,American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (1999). Standards for educational and psychological testing. Washington, DC: American Educational Research Association.) and reliable, i.e., show evidence of consistency across items and raters and over time, etc.
It is important that people who are equal on the measured construct (e.g., mathematics ability, depression) have an approximately equal probability of answering a test item accurately or acknowledging the presence of a symptom. An example of an item on a mathematics test that might be used in the United Kingdom but not the United States could be the following: "In a football match two players get a red card; how many players are left on the pitch?" This item requires knowledge of football (soccer) to be answered correctly, not just mathematical ability. Thus, group membership can influence the probability of correctly answering items, as encapsulated in the concept of differential item functioning. Often tests are constructed for a specific population and the nature of that population should be taken into account when administering tests outside that population. A test should be invariant between relevant subgroups (e.g., demographic groups) within a larger population. For example, for a test to be used in the United Kingdom, the test and its items should have approximately the same meaning for British males and females. That invariance does not necessarily apply to similar groups in another population, such as males and females in the United States or between populations, for example, the populations of the UK and the US. In test construction, it is important to establish invariance at least for the subgroups of the population of interest.
Psychological assessment is similar to psychological testing but usually involves a more comprehensive assessment of the individual. According to the American Psychological Association, psychological assessment involves the collection and integration of data for the purpose of evaluating an individual’s "behavior, abilities, and other characteristics."American Psychological Association. (n.d.). Psychological assessment. APA Dictionary of Psychology. Accessed October 11, 2023 Each assessment is a process that involves integrating information from multiple sources, such as personality inventories, ability tests, symptom scales, interest inventories, and attitude scales, as well as information from personal interviews. Collateral information can also be collected from occupational records or medical histories; information can also be obtained from parents, spouses, teachers, friends, or past therapists or physicians. One or more psychological tests are sources of information used within the process of assessment. Many psychologists conduct assessments when providing services. Psychological assessment is a complex, detailed, in-depth process. Examples of assessments include providing a diagnosis, identifying a learning disability in schoolchildren, determining if a defendant is mentally competent, and selecting job applicants.
History
The first large-scale tests may have been part of the imperial examination system in China. The tests, an early form of psychological testing, assessed candidates based on their proficiency in topics such as civil law and fiscal policies. Early tests of intelligence were made for entertainment rather than analysis. Modern mental testing began in France in the 19th century. It contributed to identifying individuals with intellectual disabilities for the purpose of humanely providing them with an alternative form of education.
Englishman Francis Galton coined the terms psychometrics and eugenics. He developed a method for measuring intelligence based on nonverbal sensory-motor tests. The test was initially popular but was abandoned. In 1905 French psychologists Alfred Binet and Théodore Simon published the Échelle métrique de l'Intelligence (Metric Scale of Intelligence), known in English-speaking countries as the Binet–Simon test. The test focused heavily on verbal ability. Binet and Simon intended that the test be used to aid in identifying schoolchildren who were intellectually challenged, which in turn would pave the way for providing the children with professional help. The Binet-Simon test became the foundation for the later-developed Stanford–Binet Intelligence Scales.
The origins of personality testing date back to the 18th and 19th centuries, when phrenology was the basis for assessing personality characteristics. Phrenology, a pseudoscience, involved assessing personality by way of skull measurement. Early pseudoscientific techniques eventually gave way to empirical methods. One of the earliest modern personality tests was the Woodworth Personal Data Sheet, a self-report inventory developed during World War I to be used by the United States Army for the purpose of screening potential soldiers for mental health problems and identifying victims of shell shock (the instrument was completed too late to be used for the purposes it was designed for). The Woodworth Inventory, however, became the forerunner of many later personality tests and scales.
Principles The development of a psychological test requires careful research. Some of the elements of test development involve the following: Standardization - All procedures and steps must be conducted with consistency from one testing site/testing occasion to another. Examiner subjectivity is minimized (see objectivity next). Major standardized tests are normed on large try-out samples in order to understand what constitutes high, low, and intermediate scores. Objectivity - Scoring such that subjective judgments and biases are minimized; scores are obtained in a similar manner for every test taker (see below). Discrimination - Scores on a test should discriminate members of extreme groups; for example, each subscale of the original MMPI distinguished hospitalized patients suffering from mental illness and members of a well comparison group. Test Norms - Part of the standardization of large-scale tests (see above). Norms help psychologists learn about individual differences. For example, a normed personality scale can help psychologists understand how some people are high in negative affectivity (NA) and others are low or intermediate in NA. With many psychoeducational tests, test norms allow educators and psychologists obtain an age- or grade-referenced percentile rank, for example, in reading achievement. Reliability - Refers to test or scale consistency. It is important that individuals score about the same if they take a test and an alternate form of the test or if they take the same test twice, within a short time window. Reliability also refers to response consistency from test item to test item. Validity - Refers to evidence that demonstrates that a test or scale measures what it is purported to measure.
Sample of behavior The term sample of behavior refers to an individual's performance on tasks that have usually been prescribed beforehand. For example, a spelling test for middle school students cannot include all the words in the vocabularies of middle schoolers because there are thousands of words in their lexicon; a middle school spelling test must include only a sample of words in their vocabulary. The samples of behavior must be reasonably representative of the behavior in question. The samples of behavior that make up a paper-and-pencil test, the most common type of psychological test, are written into the test items. Total performance on the items produces a test score. A score on a well-constructed test is believed to reflect a psychological construct such as achievement in a school subject like vocabulary or mathematics knowledge, cognitive ability, dimensions of personality such as introversion/extraversion, etc. Differences in test scores are thought to reflect individual differences in the construct the test is purported to measure.
Types There are several broad categories of psychological tests:
Achievement tests
Achievement tests assess an individual's knowledge in a subject domain. Some academic achievement tests are designed to be administered by a trained evaluator. By contrast, group achievement tests are often administered by a teacher. A score on an achievement test is believed to reflect the individual's knowledge of a subject area.
There are generally two types of achievement tests, norm-referenced and criterion-referenced tests. Most achievement tests are norm-referenced. The individual's responses are scored according to standardized protocols and the results can be compared to the results of a norming group. Norm-referenced tests can be used to underline individual differences, that is to say, to compare each test-taker to every other test-taker. By contrast, the purpose of criterion referenced achievement tests is ascertain whether the test-taker mastered a predetermined body of knowledge rather than to compare the test-taker to everyone else who took the test. These types of tests are often a component of a mastery-based classroom.
The Kaufman Test of Educational Achievement is an example of an individually administered achievement test for students.
Aptitude tests
Psychological tests have been designed to measure abilities, both specific (e.g., clerical skill like the Minnesota Clerical Test) and general abilities (e.g., traditional IQ tests such as the Stanford-Binet or the Wechsler Adult Intelligence Scale). A widely used, but brief, aptitude test used in business is the Wonderlic Test. Aptitude tests have been used in assessing specific abilities or the general ability of potential new employees (the Wonderlic was once used by the NFL).NFL Wonderlic Aptitude tests have also been used for career guidance.
Evidence suggests that aptitude tests like IQ tests are sensitive to past learning and are not pure measures of untutored ability. The SAT, which used to be called the Scholastic Aptitude Test, had its named changed because performance on the test is sensitive to training.
Attitude scales