قارن الطرق

	تقييم البرامج الطولية	تحليل السلاسل الزمنية المتقطعة (ITS)
المجال	الأساليب الميدانية	الاستدلال السببي
العائلة	Process / pipeline	Regression model
سنة النشأة	1960s–1970s (program evaluation); longitudinal designs formalized 1970s–1980s	2002
صاحب الطريقة	Peter Rossi, Michael Scriven, Donald Campbell (program evaluation tradition)	Wagner, Soumerai, Zhang & Ross-Degnan (segmented regression); Bernal, Cummins & Gasparrini (tutorial)
النوع	Applied evaluation research design	Quasi-experimental segmented regression
المصدر التأسيسي	Rossi, P. H., Lipsey, M. W., & Freeman, H. E. (2004). Evaluation: A Systematic Approach (7th ed.). Sage Publications. ISBN: 978-0761908944	Bernal, J. L., Cummins, S., & Gasparrini, A. (2017). Interrupted time series regression for the evaluation of public health interventions: a tutorial. International Journal of Epidemiology, 46(1), 348-355.
الأسماء البديلة	LPE, longitudinal evaluation, long-term program evaluation, prospective program evaluation	ITS analysis, segmented regression of time series, Kesintili Zaman Serisi (ITS) Analizi
ذات صلة	3	5
الملخص	Longitudinal program evaluation is an applied research design that tracks the outcomes and processes of a program or intervention across multiple time points — from pre-implementation baseline through medium- and long-term follow-up. Unlike single-point evaluations, it captures how program effects emerge, fade, or evolve over time, enabling evaluators and funders to judge sustained impact, cost-effectiveness, and unintended consequences that would be invisible in a snapshot assessment.	Interrupted Time Series analysis is a quasi-experimental design that estimates the effect of a single, well-dated intervention by comparing the trajectory of an outcome before and after it occurs. Formalised as segmented regression by Wagner and colleagues (2002) and popularised as a public-health evaluation tutorial by Bernal, Cummins and Gasparrini (2017), it separates the intervention's impact into a change in level and a change in slope.