So sánh phương pháp

	Khảo sát dọc	Quan sát không tham gia
Lĩnh vực	Phương pháp luận khảo sát	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1940s (panel survey tradition); longitudinal designs codified mid-20th century	Formalized mid-20th century (Gold 1958); practice dates to late 19th-century social surveys
Người khởi xướng	Established tradition; formalized in social science by Paul Lazarsfeld and colleagues (1940s panel studies)	Raymond Gold (role typology); earlier roots in social survey movement and Chicago School sociology
Loại	Quantitative / mixed-methods survey design	Qualitative / quantitative observational data collection
Công trình gốc	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922292	Gold, R. L. (1958). Roles in sociological field observations. Social Forces, 36(3), 217–223.
Tên gọi khác	panel survey, repeated-measures survey, longitudinal panel study, wave survey	detached observation, systematic observation, structured field observation, external observation
Liên quan	3	5
Tóm tắt	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.	Non-participant observation is a data-collection method in which the researcher observes behavior, interactions, or events in a natural or structured setting without joining or influencing the activity under study. The observer maintains a deliberate distance from participants to minimize their own effect on the phenomena being recorded, producing field notes, behavioral tallies, or recordings that reflect naturally occurring behavior rather than behavior shaped by researcher involvement.