Essay on validity & reliability

1475 Words Feb 4th, 2014 6 Pages

For the statistical consultant working with social science researchers the estimation of reliability and validity is a task frequently encountered. Measurement issues differ in the social sciences in that they are related to the quantification of abstract, intangible and unobservable constructs. In many instances, then, the meaning of quantities is only inferred.
Let us begin by a general description of the paradigm that we are dealing with. Most concepts in the behavioral sciences have meaning within the context of the theory that they are a part of. Each concept, thus, has an operational definition which is governed by the overarching theory. If a concept is involved in the testing of hypothesis to
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Example, a new simple test is to be used in place of an old cumbersome one, which is considered useful, measurements are obtained on both at the same time. Logically, predictive and concurrent validation are the same, the term concurrent validation is used to indicate that no time elapsed between measures.
Construct Validity:
Construct validity is the degree to which a test measures an intended hypothetical construct. Many times psychologists assess/measure abstract attributes or constructs. The process of validating the interpretations about that construct as indicated by the test score is construct validation. This can be done experimentally, e.g., if we want to validate a measure of anxiety. We have a hypothesis that anxiety increases when subjects are under the threat of an electric shock, then the threat of an electric shock should increase anxiety scores (note: not all construct validation is this dramatic!)
A correlation coefficient is a statistical summary of the relation between two variables. It is the most common way of reporting the answer to such questions as the following: Does this test predict performance on the job? Do these two tests measure the same thing? Do the ranks of these people today agree with their ranks a year ago?