When Does EdTech Work? Evidence from a Scalable Home-Based Intervention with School Complementarity

Despite growing investment in education technology, evidence on how to integrate digital tools effectively into public education systems remains limited. Substituting classroom instruction with computer-aided learning has often failed to improve outcomes, even though schools remain the most direct route to scale educational innovations. This paper studies an alternative approach: delivering personalized educational software to households, where smartphone access is widespread, while experimentally varying school involvement. We evaluate Leo Leo, an adaptive early literacy application for young children, using a randomized controlled trial in 105 public schools in Nuevo León, Mexico. Schools were assigned to either (i) a family-only intervention providing access to the app and family support, or (ii) a combined family-and-school intervention that additionally provided teachers with information on children’s progress. The same home-based technology generates gains in early literacy and numeracy only when complemented by school monitoring; the family-only intervention produces no robust learning gains. Differences in impacts are driven by children’s engagement with the software rather than changes in parental inputs. Overall, the results show that while home-based delivery of EdTech can overcome key scalability constraints, institutional involvement remains critical for translating scalable technology into learning gains.