手法を比較

	ケーススタディリサーチ（Case Study Research）	Delphi Method	エスノグラフィー
分野	質的手法	質的手法	質的手法
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1984 (seminal codification)	1963	c. 1922 (Malinowski's Argonauts of the Western Pacific)
提唱者	Robert K. Yin (systematised in Case Study Research, 1984)	Norman Dalkey & Olaf Helmer (RAND Corporation)	Bronisław Malinowski (modern ethnography); rooted in 19th-century anthropology
種類	Qualitative research design	Structured iterative expert-elicitation process	Qualitative fieldwork tradition
原典	Yin, R.K. (2018). Case Study Research and Applications: Design and Methods (6th ed.). Sage. ISBN: 978-1506336169	Dalkey, N. & Helmer, O. (1963). An Experimental Application of the Delphi Method to the Use of Experts. Management Science, 9(3), 458-467.	Hammersley, M. & Atkinson, P. (2019). Ethnography: Principles in Practice (4th ed.). Routledge. ISBN: 978-1138504462
別名	Vaka Çalışması (Case Study), case study design, case study methodology	Delphi Yöntemi, Delphi technique, expert consensus method	Etnografi, participant observation, fieldwork, ethnographic research
関連	5	5	5
概要	Case study research is a qualitative research design that investigates a specific phenomenon, individual, group, organisation, or event in depth within its real-world context. Systematised by Robert K. Yin in 1984, it supports single-case and multiple-case designs and draws on multiple data sources — interviews, observation, documents, and artefacts — to build a rich, contextualised account of a bounded unit.	The Delphi method is a structured, iterative survey technique developed by Norman Dalkey and Olaf Helmer at the RAND Corporation in 1963 for eliciting and converging expert opinion on complex topics where empirical data are unavailable or insufficient. It collects independent judgements from a geographically dispersed expert panel over multiple anonymous rounds, feeding aggregated results back to participants after each round so they can revise their views in light of the group's collective position.	Ethnography is a qualitative research tradition in which a researcher immerses themselves in a social group or community over an extended period — typically three to six months or longer — to study its culture, values, and behaviours in their natural setting. Originating in social and cultural anthropology, and consolidated as a rigorous method by Bronisław Malinowski in the early twentieth century, ethnography produces rich, contextualised accounts of how people live, work, and make meaning together.