So sánh phương pháp

	Nghiên cứu nhân quả-so sánh	Nghiên cứu mô tả	Thiết kế Ex Post Facto
Lĩnh vực	Thiết kế nghiên cứu	Thiết kế nghiên cứu	Thiết kế nghiên cứu
Họ	Process / pipeline	Process / pipeline	Process / pipeline
Năm ra đời	1964	Late 19th century; formalized in social/behavioral sciences ~1960s–1980s	1960s (systematic codification); concept used in social science from early 20th century
Người khởi xướng	Fred N. Kerlinger	Francis Galton, Karl Pearson (early empirical tradition); formalized in social science by Fred Kerlinger	Formalized by Fred N. Kerlinger; foundational treatment by Donald T. Campbell and Julian C. Stanley
Loại	Non-experimental quantitative research design	Non-experimental quantitative research design	Non-experimental quantitative research design
Công trình gốc	Kerlinger, F. N. (1964). Foundations of Behavioral Research. Holt, Rinehart and Winston.	Creswell, J. W. (2014). Research Design: Qualitative, Quantitative, and Mixed Methods Approaches (4th ed.). Sage. ISBN: 978-1452226101	Kerlinger, F. N. (1964). Foundations of Behavioral Research. Holt, Rinehart and Winston.
Tên gọi khác	ex post facto research, causal-comparative design, retrospective causal study, CCR	descriptive study, descriptive survey design, observational descriptive research, non-experimental descriptive research	after-the-fact research, retrospective non-experimental design, causal-comparative design, EPF design
Liên quan	3	3	3
Tóm tắt	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.	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.	Ex post facto design is a non-experimental quantitative research approach in which the researcher investigates a phenomenon after it has already occurred, examining pre-existing differences between groups to explore potential causal or associative relationships. Because the independent variable cannot be manipulated — it happened in the past — the design relies on careful group selection, retrospective data collection, and statistical controls to approximate causal inference without experimental intervention.