The intervention will be evaluated through a randomised control trial with 87 schools in the state of Goiás. Randomization is stratified by gender, grade and phone ownership. 57 schools have been assigned to the treatment group, while 30 have been assigned to control. Students in the treatment group will receive nudges (reminders and encouragement messages), sent twice a week, directly on their mobile phones via text messages (SMS). In case the student does not own a phone, messages will be sent to the mobile phone of his/her primary caregiver. The treatment group consists of 12,056 students, while the control group consists of 6,200 students. Within the sample of 12,056 students assigned to receive nudges, less than half (5,188) own their own mobile phone and will receive messages directly. It is also important to note that not all students in the sample have access to the internet and that those who do not can pick up the printed class material once every week and hand in assignments the following week. For the purpose of this study however, we will be able to measure their outcomes in different ways. In addition, students among the treatment group have been further randomised, in groups of 1,507 students, to receive one of eight variations in message content.
At the end of July, we will be able estimate treatment effects on access to the online platform, and assignment completion, from administrative data provided by the Secretariat. Concretely, we have requested weekly student-level data on log in activity – or face-to-face pick-up of class materials – as well as assignment completion (again, online or offline). For those with online access, we hope to get access to daily data, which would allow us to also estimate high-frequency treatment effects through event studies. Last, after face-to-face classes resume, we will have access to administrative records on student-level attendance, grades, grade repetition and enrollment status.