We present an aggregation scheme that increases power in randomized controlled trials and quasi-experiments when the intervention possesses a robust and well-articulated theory of change. Intervention studies using longitudinal data often include multiple observations on individuals, some of which may be more likely to manifest a treatment effect…

This meta-analysis summarizes research on the effects of a comprehensive, interactive web-based software (AXXX) on the development of reading competencies among kindergarteners and elementary students. Findings from seven randomized control trials and quasi-experimental studies undertaken in a variety of contexts across Canada, Australia and Kenya…