Researchers testing mobile phone instruction across five countries found that weekly phone tutorials substantially improved primary school numeracy during pandemic school closures, according to a study published in Nature.
The trials took place in India, Kenya, Nepal, the Philippines and Uganda, testing approaches to reach children during disruptions that shut schools worldwide. In low-income countries, fewer than 15% of households have internet access, while more than 70% own mobile phones. The researchers deployed interventions across 708 students in India, 1,985 in Kenya, 2,678 in Nepal, 2,469 in the Philippines and 1,308 in Uganda.
One treatment delivered weekly SMS messages containing numeracy tasks and participation prompts. A second treatment paired those text messages with an 8-week program of weekly 20-minute phone call tutorials. Instructors used the one-on-one calls to assess foundational numeracy and adapt lessons directly to each student's learning level.
Across all five countries, students receiving the phone calls and text messages gained an average of 0.321 standard deviations in numerical operations relative to control groups. Text messages alone produced a smaller average gain of 0.078 standard deviations, showing statistically significant results only in Uganda and the Philippines. The researchers estimated the phone tutoring delivers approximately 4 years of high-quality instruction per US$100 spent.
Households maintained weekly engagement rates between 70% and 80% across the trial sites. In division assessments, the combined phone and SMS treatment increased the share of students answering correctly by 13.5 percentage points from a control group mean of 14.6%. The intervention also raised scores on untaught material, increasing fraction competence by 6.4 percentage points.
Delivery models and teacher practices
In Nepal and the Philippines, the trials tested delivery mechanisms by assigning instruction to either government teachers or non-governmental organization staff. Government teachers improved learning by 0.40 operation levels across both countries, while non-governmental organization teacher aides raised student performance by 0.30 operation levels.
Learning impacts peaked in Uganda and the Philippines, where pandemic school closures lasted nearly two years. In Uganda, fourth-grade students in the control group dropped from a 17% division pass rate at baseline to 10% at endline. Fourth graders receiving the phone calls reached a 48% pass rate, exceeding the 21% baseline division rate of fifth graders in the control group.
An embedded trial in Nepal tracked whether conducting the tutoring altered the habits of government teachers. Instructors assigned to make the phone calls were 9.3 percentage points more likely to match feedback to student learning levels and were more likely to engage parents. They also showed a 15.8 percentage point increase in reporting they would choose to become teachers again.
