It has been both a challenge and a pleasure writing and revising this book. I am grateful to Patrick Proctor, who approached me while at a book launch in London ten years ago and asked me whether I would like to write a book on methods in comparative politics. Mark Kavanagh and Craig Fowlie encouraged me to write the second edition. Tom Mackie at Strathclyde University kindly reviewed the first edition, and I am indebted to Claudio Cioffi-Revilla at George Mason University, Kenneth Newton at the University of Southampton, Richard Dunphy at the University of Dundee, and Paul Pennings at Vrije Universiteit Amsterdam for their very helpful comments on the proposed second edition. This is now the third edition (thanks again to Craig Fowlie’s encouragement). This new edition clarifies and expands the methodological discussions in Part I by providing a separate treatment of each of the main comparative methods, adding a discussion of regression analysis, and expanding the critical examination of the comparison of few countries, as well as how single-country studies have a significant role to play in comparative politics. Part II includes additional examples in each of the chapters and a new chapter on the connections between comparative politics and international relations, both in looking at the influence of domestic factors on international state behaviour, and how comparative analysis, now more than ever, needs to include important international factors to explain domestic political developments. Part III expands its concluding discussions on new issues facing comparative politics.