Policy makers might argue that they have confidence in research findings because they have been generated by the application of rigorous 'scientific' procedures for sampling, data gathering, analysis and interpretation. A problem with this argument is that it takes the politics out of educational policy making. Policies not only have instrumental significance in terms of their intended effects. They also have symbolic significance for the creation of political alliances. Policymaking is often a matter of seeking compromises between disparate interest groups rather than a deduction from general principles.We will argue that policies are matters of situated judgment, and that the quality of such judgments may be improved by the study and discussion of cases. Judgment always takes context into account, whereas the study of samples always involves abstracting variables from context. Case Studies on the other hand seek a greater particularization of descriptions based on contextual analysis. Indeed we will argue that collections of such descriptions can provide a basis for not only discerning practically significant differences between cases but also practically relevant features that cases possess in common. Policy judgments may therefore be informed and educated by universal insights distilled through the constant comparison of cases.