विधियों की तुलना करें

	अनुदैर्ध्य अनुसंधान	प्रवृत्ति अनुसंधान
क्षेत्र	अनुसंधान अभिकल्प	अनुसंधान अभिकल्प
परिवार	Process / pipeline	Process / pipeline
उद्भव वर्ष	Late 19th–early 20th century; methodologically codified through the 20th century	Mid-20th century (formalised in social science methodology ~1950s–1960s)
प्रवर्तक	No single originator; foundational methodological treatments by Stuart Menard and Judith Singer & John Willett	Earl Babbie and survey research tradition
प्रकार	Quantitative (or mixed) observational research design	Quantitative longitudinal research design
मौलिक स्रोत	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922841	Creswell, J. W. (2014). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches (4th ed.). Sage. ISBN: 978-1452226101
उपनाम	longitudinal study, longitudinal design, prospective longitudinal study, repeated-measures observational study	trend study, trend survey, longitudinal trend study, time-series survey
संबंधित	4	4
सारांश	Longitudinal research is an observational design in which the same participants, groups, or units are measured repeatedly over an extended period. Rather than capturing a single snapshot, it tracks change, stability, and temporal sequencing of variables — making it the primary non-experimental strategy for studying development, growth, decline, and the unfolding of causal processes across time.	Trend research is a longitudinal quantitative design that tracks changes in a characteristic of a general population over time by surveying different, independently drawn samples at two or more time points. Unlike panel studies, the same individuals are not followed; rather, each wave draws a fresh sample from the same population, allowing researchers to detect population-level shifts in attitudes, behaviours, or conditions while avoiding the attrition and panel conditioning problems of repeated-measures designs.