Validity and Validation of Tests
In scientific inquiry, validity of statements refers to the degree to which there is empirical evidence to support the adequacy and appropriateness of these statements. More specifically, a measure is valid to the extent that it measures what is intended to measure. How vague this description may be, it makes clear that validity is not a property of a measurement instrument, but rather the interpretation of test scores and their use. In other words, how adequate and appropriate are the interpretations and uses of test scores, taking into account empirical evidence and, eventually, theoretical rationales. Validation, then, is the process through which the validity of the proposed interpretation of scores is investigated. The process of validation amounts to collecting empirical evidence to provide stable and generally accepted theoretically based interpretations of test scores (and other modes of assessment, for that matter).