Barton describes key principles shared by history and social science education. These include perspective, causation, agency, evidence and the wider area of conceptual development. He examines the centrality of these principles to understanding both history and the social sciences, and he provides examples of their application to a variety of historical and contemporary topics found in school curricula. He describes the pedagogical challenges teachers face in addressing these principles, especially in light of research on the development of students’ understanding. He argues that educational efforts would be more effective if both official curricula and local practices were more carefully designed to capitalize on areas of similarity between seemingly distinct subjects, but also cautions that this would require substantial professional development for teachers.