The complexity of the social and physical systems in which environmental policies are made affirms that there are many unmanageable contingencies that lie beyond the control of policymakers, policy analysts, and citizens. The method of context validation, justified by the epistemology of pragmatic eliminative induction, permits estimates of the proximal range of these unmanageable contingencies, thereby lower the probability of Type III errors in environmental policy analysis. The chapter focuses on the successful application of the method to ill-structured problems in areas of job training, environmental risk assessment, and highway safety and fuel conservation. It presents threats to context validity that can invalidate claims that a contextually valid problem definition has been achieved. The unresponsiveness of content analysis may be related to another threat to context validity, sub-optimal elevation. Although judgments about sub-optimal elevation appear to require prior knowledge of the complexity of knowledge system, it is the discovery of complexity that context validation is partly designed to estimate.