This paper discusses the role that impact evaluations should play in scaling up. Credible impact evaluations are needed to ensure that the most effective programs are scaled up at the national or international levels. Scaling up is possible only if a case can be made that programs that have been successful on a small scale would work in other contexts. Therefore the very objective of scaling up implies that learning from experience is possible.
This paper reviews recent randomized evaluations of educational programs in developing countries, including programs to increase school participation, to provide educational inputs, and to reform education. It then extracts some lessons for education policy and for the practice and political economy of randomized evaluations