How are educational interventions delivered at scale? A systematic mapping review

Journal article

Scaling up educational interventions remains a central yet under-theorised challenge in educational research. Although conceptual frameworks outline principles for successful scale-up, evidence on how scaling is operationalised in practice has not been systematically synthesised. This systematic mapping review synthesises 79 empirical studies of scaled-up educational interventions. Using a configurative approach, we developed and iteratively refined a coding scheme to identify and organise observable features employed during scaleup. The analysis generated a comprehensive feature map, comprising three broad dimensions (Instructor training, Intervention delivery, and Intervention sustainability) and a set of subfeatures within each. Descriptive and exploratory analyses examined patterns in feature prevalence across domains, educational settings, and reported effect sizes. The findings reveal substantial heterogeneity in scale-up design across studies. By clarifying how scale-up has been enacted across diverse contexts, this review contributes an empirically grounded feature map for analysing scale-up design and provides a foundation for future comparative and implementation-focused research

Authors: Lea, R; Stylianides, GJ; Nunes, T; Matthews, L

• Publication status: Accepted
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Review of Education
• Acceptance date: 2026-06-05
• EISSN: 2049-6613
• Language: English
• Keywords: systematic review; mapping review; education; scale-up; intervention