เปรียบเทียบวิธี

	การสัมภาษณ์แบบไม่มีโครงสร้าง	การวิจัยแบบกลุ่มสนทนา	ทฤษฎีฐานราก
สาขาวิชา	เชิงคุณภาพ	เชิงคุณภาพ	การวิจัยเชิงคุณภาพ
ตระกูล	Process / pipeline	Process / pipeline	Process / pipeline
ปีกำเนิด	Mid-20th century (Rogers ~1942; Spradley ~1979)	1940s (sociological origin); modern applied form from the 1980s–1990s	1967
ผู้ริเริ่ม	Rooted in anthropological and sociological fieldwork traditions; systematised by James P. Spradley and Carl Rogers (non-directive counselling interview)	Robert K. Merton (sociological precursor, 1940s); popularised in applied research by Richard A. Krueger	Barney Glaser and Anselm Strauss
ประเภท	Qualitative research method	Qualitative data collection method	Method
แหล่งต้นตำรับ	Spradley, J. P. (1979). The Ethnographic Interview. Holt, Rinehart and Winston.	Krueger, R.A. & Casey, M.A. (2014). Focus Groups: A Practical Guide for Applied Research (5th ed.). Sage. ISBN: 978-1483365244	Glaser, B. G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. Aldine.
ชื่อเรียกอื่น	open-ended interview, non-directive interview, in-depth interview, conversational interview	focus group discussion, FGD, group interview, Odak Grup Araştırması	GT, Grounded Theory Approach
ที่เกี่ยวข้อง	6	6	3
สรุป	An unstructured interview is a qualitative data-collection method in which the researcher enters the conversation with a broad topic or grand-tour question rather than a fixed questionnaire, allowing the participant to direct the flow and depth of the discussion. The approach prioritises the participant's own conceptual categories and narrative logic over the researcher's pre-formed agenda, making it especially powerful for exploratory inquiry into unfamiliar or complex social phenomena.	Focus group research is a qualitative data-collection method in which a trained moderator guides structured discussions with homogeneous groups of six to ten participants to explore ideas, attitudes, and perceptions on a defined topic. Developed from sociological roots in the 1940s and systematised for applied research by Krueger and Casey, the method leverages group interaction as a data source — revealing not just what people think, but how they negotiate and articulate views in a social setting.	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.