विधियों की तुलना करें

	अनुदैर्ध्य अनुसंधान	विवरणात्मक अनुसंधान
क्षेत्र	अनुसंधान अभिकल्प	अनुसंधान अभिकल्प
परिवार	Process / pipeline	Process / pipeline
उद्भव वर्ष	Late 19th–early 20th century; methodologically codified through the 20th century	Late 19th century; formalized in social/behavioral sciences ~1960s–1980s
प्रवर्तक	No single originator; foundational methodological treatments by Stuart Menard and Judith Singer & John Willett	Francis Galton, Karl Pearson (early empirical tradition); formalized in social science by Fred Kerlinger
प्रकार	Quantitative (or mixed) observational research design	Non-experimental quantitative 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	descriptive study, descriptive survey design, observational descriptive research, non-experimental descriptive research
संबंधित	4	3
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.	Descriptive research is a non-experimental quantitative design that systematically documents the characteristics, frequencies, or distributions of variables in a defined population at a given point in time. It answers 'what is' questions — who, what, when, where, and how much — without manipulating variables or drawing causal conclusions. It is one of the most widely used research designs across the social, behavioral, health, and education sciences.