International statistical comparisons of nations have become commonplace in the contemporary landscape of education policy and social science. This book engages the emergence of these international comparisons as a particular style of reasoning about education, society, and science. It examines how international educational assessments have come to dominate much of contemporary policymaking concerning school system performance, and explores the social and cultural principles embodied in them as "rationales" to shape and fashion what is possible to rectify social issues.