G Factor Theory

The degree of performance on a particular task by an individual is dependent on the ‘G’ factor and the particular ‘S’ factor (Parankimalil, 2014). In every individual the performance is characterized by the following; general (G) ability and the particular (S) ability factors. For ‘G’ factors; (1) It is constant; (2) It is used in every activity; (3) It is inborn; (4) It differs from individual to individual and; (5) The greater the ‘G’ in the individual the greater the performance on tasks. For ‘S’ factor; (1) It also differs from one individual to another; (2) It varies from task to task in an individual; (3) It is acquired in the environment.

Fig. 1 spearman’s two-factor theory In Cash (n.d.) intelligence is a collection of cognitive

Outcomes of such test sessions (the results), if used for decision making, can affect the lives and future tendencies of examinees. The decisions made from the outcomes are usually based on the quality of examinees performances. Both the tests and decisions made should be fair and impartial to all examinees, and precise.
Unfortunately no test or testing session has ever been and can never be perfect. Some human, system and natural factors constituting extraneous conditions have made it impossible to conduct test programs without imperfections. This brings us to the Error theory, which states that it is impossible to measure anything perfectly, be it physical quantity or psychological construct. It further states that “every measurement contains error”. The true value of measurement is never known, and the exact error present is also always unknown”. This theory also explains how errors inhibit accuracy of measurement, which forms one of the theoretical frameworks of this study. From the concept of this theory, it implies that all types of tests, be it standardized, teacher made, pen-on-paper, computer based tests are not error free. Schmidt and Hunter (1999) stated that all measurements - weather in physical or social sciences – contain measurement error, and that there is no such thing as error-less

These are systematic errors and random errors. Systematic errors are instrumental errors. Systematic errors are repeatable and consistent errors associated with defective equipment, faulty instrument or flawed experimental design. These errors are sometimes caused by measuring instruments that are incorrectly calibrated or are used incorrectly. Random errors are caused by humans and accidents during measurement. Random errors are natural errors that affect the results of measurement in an unpredictable and uncontrollable way. With the concept of error theory it is understood that no test is truly free from error. Even the much cherished CAT is not left out. CAT is a computer based test that makes use of computing devices to construct and administer test items on test takers, and score their performances on the test task. These devices are complex electronic gadgets that operate on artificial logic units. Although they are programmed, their system algorithms can develop fault unexpectedly. This mode of testing also relies on human operator for designs, structuring and performance. Once the human operator misses a supposed task along his line of duty, random error is introduced. These directly affect the reliability of the test. Scuro (2004) stated that random errors usually result from human and accidental eventualities. Some errors are brought about by changing experimental conditions that are beyond the control of