This brief explores how to assess whether an intervention that worked in one context can be successfully applied in another. It introduces key concepts such as generalizability, transferability, and the importance of maintaining fidelity of function while adapting form. Tools like Mid-Level Theory and J-PAL’s Generalizability Framework offer structured ways to evaluate core mechanisms and local conditions before scaling. Through real-world case studies—from deworming in Kenya to education reform in the UK—the brief highlights practical lessons for adapting, testing, and expanding interventions while ensuring they remain effective in new settings.

This brief is part of a series of five brief guides produced by the Queen Rania Foundation, based on materials developed by Prof. Howard White (presenting  the Research and Evaluation Center (REC)) for the training course titled “Impact Evaluation: Methods, Advocacy, and Scalability”. The training was funded by the Education Endowment Foundation (EEF), the BHP Foundation, and the Queen Rania Foundation.