The third edition of this popular, innovative and engaging textbook introduces students to the various methods of modern social science, explaining how these have emerged, their strengths and limitations for understanding the world in which we live, and how it is possible to combine methodological pluralism with intellectual rigour. Focussing on the debate between positivist and constructivist approaches, this new edition features contemporary research examples, expanded discussion of experimental methods, and a new emphasis on methods that have recently grown in popularity, such as process tracing and controlled randomized trials. This is the perfect textbook for students studying the philosophy of science in the context of political science or the social sciences more broadly, and it is essential reading for all those seeking to understand how different ways of knowing affect the methods we choose to study social phenomena.