A California high school where teachers and administrators were frustrated that students were continuing to look at their phones even though they'd been told over and over to put them away during class put a new policy in place this year that requires students' phones to be locked up during school hours. Since the new school year got underway earlier this month at San Mateo High School, students have been required to keep their phones in a magnetically sealed pouch, called a Yondr pouch, that administrators unlock at the end of the day. The students have each been assigned a pouch at no cost, so they have their phones in their possession, but they can't access them. The school says there's already been a positive effect on students, but some researchers think the policy isn't a good idea. California State University research psychologist Larry Rosen said students' anxiety will build if they aren't allowed to look at their phones throughout the school day, which could itself cause distraction from concentrating in class. He suggested instead that students be given what he called "technology breaks," a few minutes between lessons to check their phones