The argument-based approach to validation involves two steps; specification of the proposed interpretations and uses of the test scores as an interpretive argument, and the evaluation of the plausibility of the proposed interpretive argument. More ambitious interpretations and uses tend to involve an extended network of inferences and assumptions and require extensive evidence for their support. Simpler interpretations do not claim much, and therefore, may not require much evidential support. The evaluation of score based decisions generally requires an evaluation of the consequences of the decision rule. In any case, the claims that are being made need to be justified. (Contains 1 figure.)