Σύγκριση μεθόδων

	Έρευνα Δράσης	Έρευνα μελέτης περίπτωσης	Μέθοδος Delphi
Πεδίο	Ποιοτική Έρευνα	Ποιοτικές Μέθοδοι	Ποιοτικές Μέθοδοι
Οικογένεια	Process / pipeline	Process / pipeline	Process / pipeline
Έτος προέλευσης	1946	1984 (seminal codification)	1963
Δημιουργός	Kurt Lewin; expanded by Kemmis, McTaggart, Reason & Bradbury	Robert K. Yin (systematised in Case Study Research, 1984)	Norman Dalkey & Olaf Helmer (RAND Corporation)
Τύπος	Method	Qualitative research design	Structured iterative expert-elicitation process
Θεμελιώδης πηγή	Lewin, K. (1946). Action research and minority problems. Journal of Social Issues, 2(4), 34–46.	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.
Εναλλακτικές ονομασίες	Participatory Action Research, PAR, Collaborative Inquiry	Vaka Çalışması (Case Study), case study design, case study methodology	Delphi Yöntemi, Delphi technique, expert consensus method
Συναφείς	1	5	5
Σύνοψη	Action research is a collaborative research methodology in which researchers work with practitioners and community members to investigate a problem, implement change, and evaluate outcomes, cycling through reflection, action, and learning. Developed by Kurt Lewin (1946), action research bridges research and practice, aiming simultaneously to produce knowledge and practical improvement.	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.