PISA claims that it can extend its reach from its current core subjects of Reading, Science, Maths and problem-solving. Yet given the requirement for high levels of reliability for PISA, especially in the light of its current high stakes character, proposed widening of its subject coverage cannot embrace some important aspects of the social and aesthetic world. Verdicts on the latter often have holistic features, and there are dangers that such verdicts involve attempts to compare what cannot be compared. Judgments about the normative and the social often feature a legitimate lack of consistency.