The meaning of content validity

Abstract

The ways in which test specialists have defined content validity are reviewed and evaluated in order to determine the manner in which this validity might best be viewed. These specialists have differed in their definitions, variously associating content validity with (1) the sampling adequacy of test content, (2) the sampling adequacy of test responses, (3) the relevance of test content to a content universe, (4) the relevance of test responses to a behavioral universe, (5) the clarity of content domain definitions, and (6) the technical quality of test items. After the theoretical and practical soundness of defining content validity in terms of each of these notions is evaluated, it is concluded that these notions are best regarded as definitions of concepts other than content validity. Since no appropriate means of defining this type of validity is therefore found, it is concluded that content validity is not a useful term for test specialists to retain in their vocabulary.