This paper addresses the role of social values in educational and psychological measurement, with special attention to the consequences of testing as validity evidence. Test use depends for its legitimacy on adherence to established principles of reliability, validity, and fairness. These principles are organized within an overarching conception of construct validity. Desired reliability depends on the meaning of the construct being measured while test fairness depends on comparable construct validity across groups or settings. In the name of fairness, value judgements need to be made throughout the testing process, as they do in the name of validity throughout the validation process.