השוואת שיטות

	מחקר השוואתי-סיבתי מבוסס פאנל	הפרש-בהפרשים (דיד)
תחום	תכנון מחקר	אקונומטריקה
משפחה	Process / pipeline	Regression model
שנת המקור	1950s–1980s (formalized across educational and social science methodology literature)	1994
הוגה השיטה	Building on causal-comparative tradition (John W. Best, 1959) extended to panel data structures in social and educational research	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)
סוג	Quantitative observational research design	Causal inference / panel regression
מקור מכונן	Fraenkel, J. R., Wallen, N. E., & Hyun, H. H. (2019). How to Design and Evaluate Research in Education (10th ed.). McGraw-Hill. ISBN: 978-1260087840	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355
כינויים	panel causal-comparative design, longitudinal ex post facto research, panel ex post facto study, repeated-measures causal-comparative study	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)
קשורות	5	5
תקציר	Panel-based causal-comparative research is a quantitative observational design that tracks the same sample of participants or units across multiple time points and then compares pre-existing groups to identify differences in outcomes. By combining the temporal depth of a panel structure with the group-contrast logic of causal-comparative (ex post facto) methodology, it allows researchers to examine how naturally occurring conditions — such as treatment exposure, policy changes, or demographic characteristics — relate to outcomes over time, without experimental random assignment.	Difference-in-Differences is a causal-inference method that estimates the effect of an intervention by comparing how a treatment group and a control group change over time. Made famous by Card and Krueger's 1994 minimum-wage study and developed in Angrist and Pischke's Mostly Harmless Econometrics, it isolates the treatment effect as the difference between the two groups' before-after changes.