Introduction
A test is an objective, standardized measure of a particular behavior (Domino & Domino, 2006). The definition captures three very essential elements namely objectivity, standardization and behavior. Objectivity in this case relates to the aspects of scoring and interpreting tests. Scoring and interpreting tests are not based on the examiner’s point of view by on an objective criterion. As such, tests are free of examiner bias as results are not a reflection of personal views. On the other hand, standardization relates to the uniformity in scoring and interpretation. This ensures that under any particular test, the above aspects are carried out in the same way regardless of the person administering the test. Also, a test is used to study a sample of behavior and therefore inferences and hypotheses can be drawn from such tests (Domino & Domino, 2006). Therefore, it’s imperative for any test to satisfy the above conditions.
Categories of Tests
There are five major categories of tests including personality tests, tests of cognitive abilities, attitudes, values, interests and psychopathology (Domino & Domino, 2006). The fifth category includes tests that assess the individual’s ability to lead a normal and positive life. These tests relate to such things as self esteem and creativity. Personality tests are used to establish an individual personality which is subject to varied influences. Some of the influences include social and environmental influences (Framingham, n.d). Personality tests are used by both individuals and organizations as a primary basis of making critical decisions. At an individual level, personality tests can help an individual decide the career in which he or she is suited for. On an organizational level, such things as team selection are based on factors such as personalities of individual team members. Well known personality tests include the Minnesota Multiphasic Personality Inventory.
Tests of cognitive abilities include both intelligence tests and other tests used to explore other dimensions of cognitive functioning. Intelligence tests are popular in different circles in the society and are used to establish cognitive abilities including memory. Other cognitive abilities that are tested include verbal comprehension, processing speed and perceptual reasoning (Framingham, n.d). Cognitive abilities tests also lay a good basis for assessing neuropsychological damage on individuals that are involved in accidents.
Tests of attitudes, values and interests are commonly used to evaluate an individual’s attitudes towards various phenomenons in their environment. These tests include an aspect of self reporting where an individual is in a position to scrutinize interests, values and attitudes. Psychopathological tests are used by clinicians to establish a presence of a mental illness. Psychopathology tests form a basis from which clinicians are in a position to establish the presence of a mental illness. Consequently, steps are taken to ensure that such patients are put on appropriate recovery programs. The final category of the test includes those for normal and positive functioning (Domino & Domino 2006). These tests primarily assess aspects of self esteem where individuals assess their ability to constructively engage with at individual and group levels.
Concept of Reliability and Validity
Reliability refers to tests ability to produce similar results when presented to subjects from different populations. Therefore, a test is expected to produce consistent results across varied populations. There are several methods of establishing the reliability of a test including test-retest, internal consistency and split half reliability. Test-retest reliability explores the consistency of results from a test over a period of time. The reliability of the test is established where there is decreased variation in the results from tests presented at different times.
Furthermore, internal consistency reliability refers to the relationship between items in the test. A clear and consistent relationship between all the items in the test should be established. This ensures that all information collected from the test is consistent with the main problem under investigation. Split half reliability is recommended where the test is long (Creswell, 2003). This ensures that results from the test are compared the actual results.
Validity refers to the ability of a test to measure the phenomena or element under investigation. Validity of the test is based in three critical elements including purpose and structure of the test and population for which the test was intended for. There are four forms of validity namely content, criterion-related, and concurrent and construct validity. Content validity relates to the ability of the test items to cover all elements of the phenomena under investigation. Concurrent validity is a comparison of the test scores with those of tests carried out in the past. Construct validity, on the other hand, is tested through a comparison of actual test scores and the hypothesized test scores.
Reliability and Validity in Psychological Testing
Certain tendencies in psychological testing can either increase or decrease the reliability or validity of a test. For example, in tests where a Likert scale is used, reliability increases where test subjects resort to neutral responses (mid-point response set) as if the subject were presented with the same test, their answers would remain the same (Domino & Domino, 2006). However, this affects the validity of the test as it might not comprehensively measure the behavior under investigations.
In cases where tests have a dichotomous set of answers and such tests tend to endorse one side of the dichotomous, such a test is bias and thus affects both the reliability and validity of the test. Therefore, it’s imperative that psychological tests do not contain any leading questions as this leads to increased bias on the test. Other aspects that might interfere with reliability and validity of psychological tests include speed and accuracy. Tests might place emphasis on either speed or accuracy thus affecting the reliability and validity of the tests.
