পদ্ধতির তুলনা করুন

	দীর্ঘমেয়াদী অংশগ্রহণহীন পর্যবেক্ষণ	দীর্ঘমেয়াদী সমীক্ষা
ক্ষেত্র	জরিপ পদ্ধতি	জরিপ পদ্ধতি
পরিবার	Process / pipeline	Process / pipeline
উদ্ভবের বছর	Early–mid 20th century (systematized 1920s–1970s)	1940s (panel survey tradition); longitudinal designs codified mid-20th century
প্রবর্তক	Rooted in sociological field research traditions (e.g., Chicago School); longitudinal extension developed through 20th-century social science methodology	Established tradition; formalized in social science by Paul Lazarsfeld and colleagues (1940s panel studies)
ধরন	Longitudinal observational data collection	Quantitative / mixed-methods survey design
মৌলিক উৎস	Angrosino, M. (2007). Doing Ethnographic and Observational Research. Sage Publications. ISBN: 978-1412922173	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922292
অপর নাম	longitudinal unobtrusive observation, repeated non-participant observation, longitudinal systematic observation, extended non-participant field observation	panel survey, repeated-measures survey, longitudinal panel study, wave survey
সম্পর্কিত	4	3
সারসংক্ষেপ	Longitudinal non-participant observation is a data collection method in which a researcher systematically watches and records naturally occurring behaviors, interactions, or events at a setting over multiple, repeated observation sessions spanning weeks, months, or years — without joining or influencing the activities being observed. The researcher remains an external observer, producing a time-ordered record of change or continuity in the phenomenon under study.	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.