เปรียบเทียบวิธี

	การศึกษากรณีแบบเครื่องมือ (Instrumental Case Study)	การวิจัยเชิงปฏิบัติการ	การวิจัยกรณีศึกษา	ทฤษฎีฐานราก
สาขาวิชา	เชิงคุณภาพ	การวิจัยเชิงคุณภาพ	เชิงคุณภาพ	การวิจัยเชิงคุณภาพ
ตระกูล	Process / pipeline	Process / pipeline	Process / pipeline	Process / pipeline
ปีกำเนิด	1995	1946	1984 (seminal codification)	1967
ผู้ริเริ่ม	Robert E. Stake	Kurt Lewin; expanded by Kemmis, McTaggart, Reason & Bradbury	Robert K. Yin (systematised in Case Study Research, 1984)	Barney Glaser and Anselm Strauss
ประเภท	Qualitative research method	Method	Qualitative research design	Method
แหล่งต้นตำรับ	Stake, R. E. (1995). The Art of Case Study Research. Sage Publications. ISBN: 978-0803957671	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	Glaser, B. G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. Aldine.
ชื่อเรียกอื่น	instrumental case research, theory-building case study, illustrative case study, issue-driven case study	Participatory Action Research, PAR, Collaborative Inquiry	Vaka Çalışması (Case Study), case study design, case study methodology	GT, Grounded Theory Approach
ที่เกี่ยวข้อง	6	1	5	3
สรุป	Instrumental case study is a qualitative research design, formalised by Robert E. Stake (1995), in which a specific case is studied primarily to gain insight into an external issue or theoretical question — not because the case itself is intrinsically important. The case serves as an instrument for understanding something broader: a policy problem, a theoretical proposition, or a generalised phenomenon. One or several cases are selected because they are expected to illuminate the issue particularly well, and the researcher moves fluidly between the case and the issue throughout the study.	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.	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.