So sánh phương pháp

	Nhóm tập trung dọc	Khảo sát 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	1940s (panel survey tradition); longitudinal designs codified mid-20th century
Người khởi xướng	Adapted from Robert K. Merton's focused interview tradition; longitudinal design developed in social and health sciences	Established tradition; formalized in social science by Paul Lazarsfeld and colleagues (1940s panel studies)
Loại	Qualitative longitudinal data collection	Quantitative / mixed-methods survey design
Công trình gốc	Morgan, D. L. (1997). Focus Groups as Qualitative Research (2nd ed.). Sage Publications. ISBN: 978-0761903437	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922292
Tên gọi khác	repeated focus group, panel focus group, longitudinal FG, follow-up focus group	panel survey, repeated-measures survey, longitudinal panel study, wave survey
Liên quan	5	3
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.	A longitudinal survey collects structured questionnaire data from the same individuals or units at two or more distinct points in time. By tracking the same respondents across waves, researchers can distinguish genuine change from stable individual differences, establish temporal ordering between variables, and model trajectories of attitudes, behaviors, or outcomes in ways that a single cross-sectional snapshot cannot support.