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

Abstract

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 scale‐up. The analysis generated a comprehensive feature map, comprising three broad dimensions (Instructor training, Intervention delivery and Intervention sustainability) and a set of sub‐features 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.