Psychometrics Essay Example | Topics and Well Written Essays - 1000 words

Psychometrics - Essay Example The tests used are designed strictly for this purpose and has no relevance to anything else other than the purpose for which it was created (Rust & Golombok, 1989). Measurement in psychometrics can be taken as the conversion of abstract constructs into concrete variables on the basis of a clear set of rules and arises from the conjecture of McCall 1939 p.15, that â€Å"anything that exists in amount can be measured.† Tests form the essential feature of the means to measurement in psychometrics. A test may be taken as a standard procedure in an attempt to sample behaviour and describe it in terms of categories or scores. A true test incorporates norms and standards in relation to the scores that assist in the prediction of behaviour and performance. An unstandardised test has confounding factors in it, which interact with the performance and as a result has a negative impact on the ability to evaluate performance. Psychological testing attempts to ape measurements in the physical measurement, where numbers are ascribed to demonstrate levels of some feature like temperature or weight. Tests through its scores or evidence make it possible to assess whether an individual belongs to a particular category or group and to evaluate the quantum of trait or quality that is possessed by the individual. There are two caveats that govern any test. The first caveat is that error is inherent to a test result and that the measurement obtained is not a reflection of the true score, but a reflection of the sum of the true score and the error, which may be positive or negative. The second caveat is that psychological test scores are not a measure of physical reality and are representative of abstract concepts. For example the Intelligence Quotient (IQ) does not really exist, but is a useful abstract concept for predicting success in academics or career. Test scores are interpreted through the comparison against a set of