This case illustrates ideas about systematic reviews of evidence and meta-analysis in a stepwise fashion. Presented is a discussion about studies of the effectiveness of interventions that are designed to prevent school dropout in low and low to middle income countries and to use tests in high-quality randomized controlled trials and high-quality quasi-experiments. The coverage includes framing the questions, searching literature, computing effect sizes, and portraying results on 'what works'. [This content is provided in the format of an e-book.]