Σύγκριση μεθόδων

	Διαχρονική Μελέτη Περίπτωσης	Έρευνα Δράσης	Θεμελιωμένη Θεωρία
Πεδίο	Ποιοτικές Μέθοδοι	Ποιοτική Έρευνα	Ποιοτική Έρευνα
Οικογένεια	Process / pipeline	Process / pipeline	Process / pipeline
Έτος προέλευσης	1984–1990 (foundational methodological codification)	1946	1967
Δημιουργός	Robert K. Yin (case study methodology); Andrew M. Pettigrew (longitudinal field research)	Kurt Lewin; expanded by Kemmis, McTaggart, Reason & Bradbury	Barney Glaser and Anselm Strauss
Τύπος	Qualitative research design	Method	Method
Θεμελιώδης πηγή	Yin, R. K. (2018). Case Study Research and Applications: Design and Methods (6th ed.). Sage. ISBN: 978-1506336169	Lewin, K. (1946). Action research and minority problems. Journal of Social Issues, 2(4), 34–46.	Glaser, B. G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. Aldine.
Εναλλακτικές ονομασίες	longitudinal case research, panel case study, repeated case study, temporal case study	Participatory Action Research, PAR, Collaborative Inquiry	GT, Grounded Theory Approach
Συναφείς	6	1	3
Σύνοψη	A longitudinal case study is a qualitative research design that combines the in-depth, contextually rich focus of case study methodology with repeated data collection across multiple time points. Rather than capturing a single snapshot, it follows one or a small number of cases — an individual, group, organisation, or programme — over months or years to trace how processes, relationships, and meanings evolve. This design is well suited to questions about how and why things change, not merely what the state of affairs is at one moment.	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.	Grounded Theory (GT) is a systematic qualitative research methodology in which theory emerges directly from data through iterative analysis, rather than being imposed before data collection. Developed by Barney Glaser and Anselm Strauss in 1967, GT prioritizes generating explanatory frameworks grounded in evidence.