Linganisha mbinu

	Utafiti wa Longitudinal	Utafiti wa Cohort	Utafiti
Nyanja	Metodolojia ya Dodoso	Epidemiolojia	Metodolojia ya Dodoso
Familia	Process / pipeline	Process / pipeline	Process / pipeline
Mwaka wa asili	1940s (panel survey tradition); longitudinal designs codified mid-20th century	Mid-20th century (formal epidemiological design codified ~1950s)	Late 19th century; systematic social-science use from 1940s
Mwanzilishi	Established tradition; formalized in social science by Paul Lazarsfeld and colleagues (1940s panel studies)	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Francis Galton, Charles Booth, and early social statisticians; formalised by Paul Lazarsfeld in the 1940s
Aina	Quantitative / mixed-methods survey design	Observational longitudinal study design	Quantitative (primarily) or mixed-methods data-collection instrument
Chanzo asilia	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922292	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	Dillman, D. A., Smyth, J. D., & Christian, L. M. (2014). Internet, Phone, Mail, and Mixed-Mode Surveys: The Tailored Design Method (4th ed.). Wiley. ISBN: 978-1118456149
Majina mbadala	panel survey, repeated-measures survey, longitudinal panel study, wave survey	longitudinal study, follow-up study, panel study, incidence study	questionnaire survey, survey research, self-report survey, questionnaire study
Zinazohusiana	3	6	6
Muhtasari	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.	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.	A survey is a systematic data-collection method in which a standardised set of questions is posed to a sample of respondents to measure attitudes, behaviours, demographics, or other constructs. Surveys can be administered via paper, telephone, online platforms, or face-to-face. They are among the most widely used instruments in social, behavioural, health, and educational research because they can reach large, geographically dispersed samples at relatively low cost.