So sánh phương pháp

	Độ bão hòa dữ liệu trong nghiên cứu định tính	Phương pháp nhóm tập trung
Lĩnh vực	Nghiên cứu định tính	Nghiên cứu định tính
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1967	1956
Người khởi xướng	Barney Glaser and Anselm Strauss	Robert K. Merton and Paul F. Lazarsfeld
Loại	Concept	Method
Công trình gốc	Glaser, B. G., & Strauss, A. L. (1967). The Discovery of Grounded Theory: Strategies for Qualitative Research. Aldine. ISBN: 978-0202302560	Krueger, R. A. (1994). Focus Groups: A Practical Guide for Applied Research. SAGE Publications. ISBN: 978-0803954366
Tên gọi khác	saturation, theoretical saturation, thematic saturation, sampling to saturation	FGD, focus group discussion, group interview
Liên quan	4	4
Tóm tắt	Data saturation is a foundational principle in qualitative research describing the point at which data collection yields no new themes, codes, or insights—additional data becomes redundant. Introduced by Glaser and Strauss (1967) in their work on grounded theory, saturation guides decisions about sample size and when to stop recruiting participants. Saturation is not a fixed number but a dynamic endpoint determined by examining whether new data are adding substantively new information. The concept is central to claims of rigor and theoretical adequacy in qualitative research, signaling that the researcher has gathered sufficient data to understand the phenomenon in depth.	Focus group discussions are a qualitative research method in which a trained moderator guides a small group (typically 6–12 participants) through structured or semi-structured discussion of a specific topic or product. Developed by Merton and Lazarsfeld in the 1950s for market research, focus groups are now widely used in health sciences, education, social sciences, and policy research. The method leverages group interaction to generate rich, contextual insights that individual interviews may not reveal.