Personality Assessments
In the early times, psychological tests were used to measure intelligence and detect personality disorders. As defined by Robert Gregory in his 1996 book, “Psychological Testing: History, Principles and Applications”, a psychological test is “a standardized procedure for sampling behaviour and describing it with categories or scores”. To aid the interpretation of such categories or scores, norms or standards have been set as basis for comparison. Standardization of a test is valid provided that the procedures for administration of the test are uniform and consistent.
Before a test will be considered standardized, a test should establish norms or standards. Norms are “summaries of test results for a large and representative group of subjects” called the “sample”. Aside from indicating the required average performance, the norms also indicate the degree to which a score compares with the expectations. The selection of the standardization sample is also highly significant. The sample should be “representative of the population for whom it is intended”. The validity and reliability of the test is also highly emphasized. A test is considered valid if it measures what it intends to measure. Reliability of a test refers to the consistency of the scores a test-taker gets, regardless of the examiner, the setting, the time or the date.
Psychological tests can be either norm-referenced or criterion-referenced. For norm-referenced tests, examinee’s performance is interpreted through a comparison against the standardization sample. For criterion-referenced tests, an examinee is judged as to where he stands in pre-set categories. Tests can also be grouped into individual tests that should be administered one-to-one or group tests that are suitable to administering to groups of examiners at the same time. These tests can also be classified under intelligence tests, aptitude tests, achievement tests, creativity tests, personality tests, interest inventories, behavioural assessments, and neurophysiological tests. Psychological tests are now widely used in placement, screening, certification, selection and diagnosis and treatment.