A general framework is provided for examining the validity of performance standards for high-stakes achievement tests. The emphasis is on conceptual issues and broadly defined methodological questions, the types of validity evidence that can be collected, and the advantages and limitations of different types of evidence. Validation consists of a demonstration that the proposed passing score can be interpreted as representing the level of achievement specified in the proposed performance standard. The performance standard is the conceptual version of the desired level of competence, and the passing score is the operational version of the desired level of competence. The analysis addresses the question of the arbitrariness of the passing score by identifying two assumptions that are involved in adopting a passing score. The first is that it corresponds to a specified performance standard, and the second is that the specified standard is appropriate. Support for the first, descriptive, assumption is to be derived mainly from procedural evidence and internal validity checks. Support for the policy assumption is to be derived mainly from procedural evidence and external validity checks. Even if all available checks on the validity of the standard are implemented, the best that can be done is to show that the proposed standard is reasonable or acceptable. (Contains 79 references.) (SLD)