Validity

Validity is a central concept in social science research. At the broadest level, validity refers to the extent to which a claim, result, inference, or argument is well founded. In the social sciences, the term validity is often (but not exclusively) used in reference to educational and psychological measurement and assessment, where it is frequently referred to as the most fundamental consideration in developing and evaluating tests. However, despite wide agreement regarding its importance, there is no single conception of validity universally accepted in the scholarly and professional communities, and there remains considerable controversy surrounding the definition of validity and many related concepts and terms.

This entry introduces the topic of validity, concentrating on its applications in measurement and assessment. The entry begins with an overview of basic concepts and terminology, followed by sections describing perspectives on validity and validation roughly following a historical progression. Early perspectives on validity are described first, including the concepts of criterion- and content-related forms of validity. The next section discusses construct validity, as first introduced by Lee J. Cronbach and Paul E. Meehl in the mid-1950s, and the idea of nomological networks. Following this are discussions of the unified perspective on validity due primarily to Samuel S. Messick and the interpretive argument-based approach to validation due primarily to Michael T. Kane. The final section discusses a causal perspective on validity due primarily to Denny Borsboom.

Although this entry does not aim to provide a thorough historical overview of thinking about validity, this historical presentation may nonetheless be helpful in contextualizing the origins of many common ways of thinking about validity, especially insofar as each of these perspectives remain influential, to varying degrees, in different areas of contemporary social scientific scholarship. This entry does not aim to provide an introduction to how validation activities do or should take shape in any given application.