เปรียบเทียบวิธี

	การวิจัยการศึกษาด้วยวิธีผลต่างในผลต่าง	Difference-in-Differences (DiD)
สาขาวิชา	การอนุมานเชิงสาเหตุ	เศรษฐมิติ
ตระกูล	Regression model	Regression model
ปีกำเนิด	1990s–2000s	1994
ผู้ริเริ่ม	Dynarski, Card, Angrist, and colleagues — applied in education economics from the 1990s onward	Card & Krueger (canonical 1994 application); Angrist & Pischke (textbook treatment)
ประเภท	Quasi-experimental causal inference	Causal inference / panel regression
แหล่งต้นตำรับ	Dynarski, S. M. (2003). Does Aid Matter? Measuring the Effect of Student Aid on College Attendance and Completion. American Economic Review, 93(1), 279-288.	Angrist, J. D., & Pischke, J.-S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton University Press. ISBN: 978-0691120355
ชื่อเรียกอื่น	DiD in education, education DiD, quasi-experimental education design, education policy DiD	diff-in-diff, DiD, Farkların Farkı (Diff-in-Diff)
ที่เกี่ยวข้อง	5	5
สรุป	Difference-in-Differences (DiD) in education research applies the classic quasi-experimental DiD estimator to evaluate education policies, programs, and reforms. Researchers compare changes in student, school, or district outcomes between a group exposed to an intervention and a comparable unexposed group across pre- and post-intervention periods, isolating policy effects from background trends.	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.