Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We assess the effectiveness of an intervention aimed at improving the reading skills of struggling third-grade students in Colombia. In a series of randomized experiments, students participated in remedial tutorials conducted during school hours in small groups. Trained instructors used structured pedagogical materials that can be easily scaled up. Informed by the outcomes of each cohort, we fine-tuned the intervention tools for each subsequent cohort. We found positive and persistent impacts on literacy scores and positive spillovers on some mathematics scores. The effectiveness of the program grew over time, likely because of higher dosage and the fine-tuning of materials.