قارن الطرق

	الفرق في الفروق (Diff-in-Diff)	التجربة الميدانية
المجال	الاقتصاد القياسي	التصميم التجريبي
العائلة	Regression model	Process / pipeline
سنة النشأة	1994	1920s–1930s (agriculture); 1990s–2000s (social sciences)
صاحب الطريقة	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)	Formalized by R. A. Fisher (1935); systematized in social sciences by Harrison & List (2004)
النوع	Causal inference / panel regression	Experimental design
المصدر التأسيسي	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355	Harrison, G. W., & List, J. A. (2004). Field experiments. Journal of Economic Literature, 42(4), 1009–1055.
الأسماء البديلة	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)	field trial, natural field experiment, randomized field experiment, field RCT
ذات صلة	5	5
الملخص	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.	A field experiment applies the logic of a randomized controlled trial in a naturally occurring, real-world environment rather than an artificial laboratory. Participants are randomly assigned to treatment and control conditions while going about everyday activities, allowing researchers to estimate causal effects with high internal validity while preserving a level of ecological realism that laboratory settings cannot offer. The design is especially prominent in economics, public health, political science, and development research.