New large-scale research examines whether restricting student phone use can improve learning and classroom conditions, with results showing measurable reductions in on-campus phone activity after schools adopted magnetic locking pouches. Researchers at Stanford, Duke, the University of Pennsylvania, and the University of Michigan analyzed data from more than 40,000 schools using Yondr. The study found cellphone “pings” dropped by 30% after schools implemented pouches, alongside teacher reports of less nonacademic phone use in class. The broader evidence base remains mixed across settings, with impacts varying by student subgroup and implementation—highlighting how real-world policy effects can differ from lab-style expectations.