So sánh phương pháp

	Nhóm tập trung dọc	Phỏng vấn sâu theo chiều dọc
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1940s (focus groups); longitudinal variant refined 1980s–1990s	1990s–2000s (as a formalised qualitative method)
Người khởi xướng	Adapted from Robert K. Merton's focused interview tradition; longitudinal design developed in social and health sciences	Rooted in qualitative longitudinal research traditions; systematised by Johnny Saldana
Loại	Qualitative longitudinal data collection	Qualitative longitudinal data collection technique
Công trình gốc	Morgan, D. L. (1997). Focus Groups as Qualitative Research (2nd ed.). Sage Publications. ISBN: 978-0761903437	Saldana, J. (2003). Longitudinal Qualitative Research: Analyzing Change Through Time. AltaMira Press. ISBN: 978-0759103917
Tên gọi khác	repeated focus group, panel focus group, longitudinal FG, follow-up focus group	repeated in-depth interview, longitudinal qualitative interview, panel qualitative interview, longitudinal IDI
Liên quan	5	5
Tóm tắt	A longitudinal focus group convenes the same group of participants in multiple sessions over an extended period — weeks, months, or years — to trace how their attitudes, experiences, or interpretations evolve in response to changing circumstances. Unlike a single focus group snapshot, the repeated-contact design captures the dynamics of opinion and meaning-making across time, making it particularly valuable in health, policy, and social research where change is the phenomenon of interest.	Longitudinal in-depth interviewing is a qualitative data collection technique in which the same participants are interviewed in depth on multiple occasions across a defined time span. By revisiting the same people over weeks, months, or years, researchers can trace how experiences, identities, attitudes, and meanings change — something a single interview cannot reveal. It is widely used in life-course research, health studies, education, and social policy.