So sánh phương pháp

	Nghiên cứu thuần tập	Phương pháp Nhật ký
Lĩnh vực	Dịch tễ học	Phương pháp luận khảo sát
Họ	Process / pipeline	Process / pipeline
Năm ra đời	Mid-20th century (formal epidemiological design codified ~1950s)	1920s–1940s (systematised by Allport, 1942)
Người khởi xướng	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Gordon Allport (systematic social-science use); Nels Anderson (early fieldwork diaries)
Loại	Observational longitudinal study design	Qualitative / mixed-methods data-collection technique
Công trình gốc	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	Alaszewski, A. (2006). Using Diaries for Social Research. Sage. ISBN: 978-0761941415
Tên gọi khác	longitudinal study, follow-up study, panel study, incidence study	diary study, diary technique, self-report diary, daily diary method
Liên quan	6	5
Tóm tắt	A cohort study assembles a group of individuals who share a common starting point — typically freedom from the outcome of interest — and follows them over time to observe who develops the outcome. By comparing incidence rates between exposed and unexposed subgroups, researchers can estimate relative risk and absolute risk differences. Cohort studies are the gold-standard observational design for measuring disease incidence and establishing temporal relationships between exposure and outcome.	The diary method is a data-collection technique in which participants record their thoughts, behaviours, events, or experiences in their own words at regular or event-contingent intervals over a defined study period. By capturing data close in time to the event, diaries reduce retrospective recall bias and give researchers access to the texture of everyday life as it unfolds — something one-off surveys and retrospective interviews cannot provide.