Which sociologist first used the case study method in his fieldwork?

The sociologist who is widely credited with pioneering the use of the case study method in fieldwork is Max Weber. Weber, a German sociologist and one of the founding figures of sociology, employed the case study method extensively in his research. He utilized detailed, in-depth studies of specific social phenomena, institutions, and individuals to develop rich understandings of complex social processes.

Weber's approach to the case study method emphasized the importance of context, historical analysis, and qualitative data in sociological research. His influential works, such as "The Protestant Ethic and the Spirit of Capitalism," utilized case studies to illustrate broader sociological concepts and theories. Weber's methodological innovations laid the groundwork for the use of case studies in sociology and other social sciences, shaping contemporary approaches to qualitative research and ethnography.