Introduction to Psychological Testing PaperThe etymology of the word test, as suggested by the Oxford English Dictionary, pictures the cup used to capture the purified gold or silver after it has been smelted (Hogan, 2007). The imagery depicts the test as the mechanism by which pure knowledge (gold and silver) is captured and ancillary information (dross) is disregarded as irrelevant. The Standards for Educational and Psychological Testing defines test as, “An evaluative device or procedure in which a sample of an examinee’s behavior [is]…evaluated and scored using a standardized process” (Hogan, 2007, p. 38). Anastasi and Cronbach, both classical textbook authors, define the term test as, “an objective and standardized measure of a sample of behavior” (p. 38) and “…a systematic procedure for observing behavior and describing it with the aid of numerical scales or fixed categories” (p. 38), respectively (Hogan, 2007). Pulling from all of these definitions Hogan (2007) proposes six critical elements of the definition of test. Collectively, these six elements explain that a test is a procedure or device used to yield quantifiable, measurable information about behavior and cognitive processes through a systematic, standardized procedure. However, this concise definition is only a starting point for understanding how testing is used to further the ends of psychological exploration. A more comprehensive understanding must consider the basic assumptions, major categories, uses, users, validity, and reliability of testing, as it pertains to psychology.
Basic AssumptionsThe use of tests in psychology presupposes several assumptions that are foundational to the advent and implementation of any psychological measure. First, examiners must suppose that individual traits and characteristics are measureable, quantifiable, able to be differentiate between individuals, and that the traits describe potentially important aspects of the individual (Hogan, 2007). Second, it must be presumed that these traits and characteristics are reasonably permanent and consistent, so that fluctuations are kept to a minimal. Last, an examiner must be able to observe traits and characteristics through some type of observable behavior. If not, then it would be impossible to quantify the underlying construct. With these assumptions in mind, there are many ways to define psychological tests. The concise definition has already been covered above. Psychological tests can also be classified and defined by the uses of the tests and the people who use the test. What is more, in the field of psychology there are five general categories by which tests are divided.
Major CategoriesThe first major category of psychological testing encompasses the quantification of mental abilities—through both individually and group administered tests—that measure intelligence, memory, quantitative reasoning, creative thinking, vocabulary, and spatial ability (Hogan, 2007). On the other hand, achievement tests are specifically design to measure knowledge or skills in one particular area—rather than generally—and are administered through the avenues of certifications, licensing, government-sponsored programs, batteries, single-subject tests, and individual achievement tests. Third, personality tests entail using objective personality tests, projective techniques, and other miscellaneous techniques in order to elucidate human personality. The last two categories explore measures of interest and attitudes, and neuropsychology largely through the use of vocational interest measures and tests of brain functioning, respectively.
Uses and UsersThere is no clear-cut distinction between the test used and the context in which it is utilized; however, each context does predominantly use one or more tests (Hogan, 2007). Psychological tests are primarily used in clinical, educational, personnel, and research contexts. Clinical situations entail the use of psychological testing in order to facilitate counseling, school psychology, clinical psychology, and neuropsychology through the use of intelligence tests, objective personality tests, and projective techniques (Hogan, 2007). In the clinical context professional psychologists are usually the examiner and the examinee is someone who has some type of psychological problem. Alternatively, the educational context is most concerned with the use of ability and achievement tests by teachers and educational facilitators to verify student learning or to calculate academic success. Third, ability and personality tests are used in a personnel framework by businesses and the military to choose among applicants for a specific position or to assign already employed individuals to their optimal positions. Last, the research context pertains to the use of the full spectrum of psychological tests as the dependent variable in experiments, describing samples, or even research on the tests themselves.
Reliability and ValidityTest reliability and test validity are tools used to measure the sustainability and effectiveness of a test. Reliability specifically refers to the consistency, replicability, and dependability of the psychometric results of a test (Hogan, 2007). To be more precise, reliability does not deal with constant errors—errors that universally affect the score of all individuals on the trait being measure—but only unsystematic errors or fluctuations in scores due to different people conducting the test, different instruments being used in the test, or a variation in measurement conditions (Dimitrov, 2010). Conversely, validity is concerned with the explication of test results to a particular interpretation. The interest here is not in the test itself but for the use or purpose of the test. At a very basic level validity entails the applicability of the scores on a test to the trait or construct that is being measured. In particular, a test should never be used for a different clinical purpose than it was originally intended. If that happens, then the test’s reliability and the interpretation’s validity will be very low (Friberg, 2010). In sum, reliability is wholly concerned with the consistency, replicability, and dependability of the measure being used in a test, and validity involves the applicability of the measure to the use or purpose of the test. Furthermore, it is important to note that for a test to be valid it must be reliable, but a test can be reliable without being valid.
ConclusionIn all, psychological tests measure trait and characteristic constructs through the use of ability, achievement, personality, interests and attitudes, and neuropsychological tests, to the end of interpreting the results for some use or purpose—within the confines of the aforementioned assumptions. The measures are used in the full plethora of clinical, educational, personnel (business and military), and research contexts. The reliability of these measures are ascertained by considering the unsystematic errors that might render the results unreplicable or inconsistent. Moreover, the validity of a test result, as it is applies to a specific use or purpose, is built upon the applicability of a set of test scores to the construct being measured. In conclusion, once a test has been deemed reliable, used in its proper context, and applied specifically to a purpose or use (valid) it has been smelted into the cup.
ReferencesDimitrov, D.M. (2010). Contemporary treatment of reliability and validity in educational assessment. Mid-Western Educational Research, 23(1), 23-28. Retrieved July 18, 2010, from Educational Research Complete Database.
Friberg, J.C. (2010). Considerations for test selection: How do validity and reliability impactdiagnostic decisions. Child Language Teaching & Therapy, 26(1), 77-92. Retrieved July 18, 2010, from Communication & Mass Media Complete Database.
Hogan, T.P. (2007). Psychological testing: A practical introduction (2nd ed.). Hoboken, NJ: Wiley.