Online tutoring works:experimental evidence from a program with vulnerable children

We provide evidence from a randomized controlled trial on the effectiveness of a novel, 100-percent online math tutoring program, targeted at secondary school students from highly disadvantaged neighborhoods. The intensive, eight-week-long program was delivered in groups of two students during after-school hours, mostly by qualified math teachers. The intervention significantly increased standardized test scores (+0.26 SD) and end-of-year math grades (+0.49 SD), while reducing the probability of repeating the school year. The intervention also raised aspirations, as well as self-reported effort at school. The two-on-one design allows us to significantly reduce costs and improve scalability, while showing similar results as one-on-one tutoring programs.