This encyclopedia is an interdisciplinary reference work with nearly 2,000 entries from the fields of methodology, qualitative and quantitative methods, and statistics. It addresses practical research topics as well as the fundamentals of empirical social research. The methods in the individual disciplines are systematically presented in detailed articles. Over 100 methodologists from sociology, political science, communication and media studies, history, ethnology and cultural anthropology, social psychology, educational sciences, health sciences, as well as social and cultural geography have contributed to the encyclopedia. It serves as a knowledge base for study and research, as well as for practice in social science professions.