High school students preparing to take college entrance exams — and their parents — may be starting to worry about how best to prepare. SAT coaching can be expensive. And though parents may try to urge their students to exert some willpower when it comes to studying for the tests, two surveys of nearly 20,000 high schoolers suggest this may not be the most successful approach. There are better ways to help keep kids motivated.

The study, by Chayce Baldwin of the University of Michigan, Ann Arbor and Angela Duckworth of the University of Pennsylvania in partnership with the College Board, was designed to test how well self-control strategies worked in a real-world situation like preparing for a big test.

Implementing one or more self-control strategies was associated with more time spent practicing for the SAT exam and higher SAT scores.

Students taking the surveys were asked about how they studied for the SAT exam used by many colleges to make admission decisions. Options included disabling their cell phones, working in a distraction-free location, setting a strict study schedule or just willing themselves to study.

The results showed that implementing one or more self-control strategies was associated with more time spent practicing for the SAT exam and higher SAT scores. The findings held up even when socioeconomic differences and students’ prior achievement were taken into account.

Students who used more self-control strategies tended to have higher scores, but each strategy’s value diminished as more strategies were used, suggesting that students may need to only rely on one or two strategies to benefit. For example, setting aside a half hour for test prep and turning off their phones during that time could be a good way for students to improve their scores.

Parents and caregivers may find that encouraging students to use self-control strategies could be a cost-effective way to help kids boost their SAT scores without the expense of tutoring, the researchers suggest. They might want to sit down with their high schoolers to choose a strategy or strategies they believe will help harness self-control and help kids prepare for the tests ahead.

The study is published in PLOS ONE.