قارن الطرق

	التجربة العشوائية العنقودية	التجربة الميدانية
المجال	البحوث السريرية	التصميم التجريبي
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1999-2000	1920s–1930s (agriculture); 1990s–2000s (social sciences)
صاحب الطريقة	Campbell, Grimshaw, Elbourne et al.	Formalized by R. A. Fisher (1935); systematized in social sciences by Harrison & List (2004)
النوع	Research Design	Experimental design
المصدر التأسيسي	Campbell, M. K., Grimshaw, J. M., & Elbourne, D. R. (2000). Intracluster correlation coefficients in cluster randomized trials: empirical insights into how should they be reported. BMC Medical Research Methodology, 4, 30.	Harrison, G. W., & List, J. A. (2004). Field experiments. Journal of Economic Literature, 42(4), 1009–1055.
الأسماء البديلة	CRT, cluster RCT, cluster trial, group randomization	field trial, natural field experiment, randomized field experiment, field RCT
ذات صلة	3	5
الملخص	A cluster randomized trial (CRT) randomizes intact groups—schools, clinics, villages, or hospital wards—rather than individuals. Developed by Campbell, Grimshaw, and colleagues in the late 1990s to address real-world settings where intervention delivery or contamination occurs at the group level, CRTs are now standard for evaluating population-level, community-based, and policy interventions.	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.