All good research is dependent upon good research design, but comparative research - and especially research in comparative politics - is more dependent than most. Some initial choices in the research design will determine the utility and validity of the research, so the logic of making those choices must be understood thoroughly. In this clear, accessible but sophisticated text, Guy Peters highlights the many decisions that must be made about research, including the number of cases, the similarity of cases, and the types of analytical techniques that should be used. He highlights the importance of theory in social research, and shows how a wide range of case-based and statistical research can produce useful findings, provided that the methods chosen are appropriate to the subject and objectives of the enquiry. A central focus is on the logic of research and understanding potential sources of error in order to maximize the reliability and validity of findings. Drawing on a wide range of approaches to comparative research, this substantially revised and updated successor to the authors classic text Comparative Politics is essential reading for anyone wanting to understand or conduct research in this major area of political science.