Sammenlign metoder

	Kausal-komparativ forskning – Retrospektiv gruppesammenligningsdesign	Longitudinal Research
Fagfelt	Forskningsdesign	Forskningsdesign
Familie	Process / pipeline	Process / pipeline
Opprinnelsesår	1964	Late 19th–early 20th century; methodologically codified through the 20th century
Opphavsperson	Fred N. Kerlinger	No single originator; foundational methodological treatments by Stuart Menard and Judith Singer & John Willett
Type	Non-experimental quantitative research design	Quantitative (or mixed) observational research design
Opprinnelig kilde	Kerlinger, F. N. (1964). Foundations of Behavioral Research. Holt, Rinehart and Winston.	Menard, S. (2002). Longitudinal Research (2nd ed.). Sage Publications. ISBN: 978-0761922841
Alias	ex post facto research, causal-comparative design, retrospective causal study, CCR	longitudinal study, longitudinal design, prospective longitudinal study, repeated-measures observational study
Relaterte	3	4
Sammendrag	Causal-comparative research is a non-experimental quantitative design in which the researcher compares two or more groups that already differ on an independent variable — one that was not manipulated — to investigate possible causes or consequences of that difference. Because group membership is pre-existing rather than randomly assigned, the design can suggest causal relationships but cannot establish them with the certainty of a true experiment. It is widely used in education, psychology, and social sciences when experimental manipulation is impractical or unethical.	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.