"Impact evaluations aim to measure the outcomes that can be attributed to a specific policy or intervention. Although there have been excellent reviews of the different methods that an evaluator can choose in order to estimate impact, there has not been sufficient attention given to questions...

"More attention and resources have been devoted in recent years to early childhood development (ECD) in low- and middle-income countries. Rigorous studies on the effectiveness of ECD-related programs for improving children's development in various dimensions in the developing world are scant....