Some of the challenges that stymie high school teachers about their students have been around for generations. Neglecting homework. Arriving to class late. Dozing off.

But for the past 15 years or so, there’s been an even more pernicious obstacle facing teachers: students constantly distracted by their cellphones.

Officially, some high schools prohibit the use of cellphones in class and others leave it up to teachers’ discretion, but enforcement is almost impossible. A teacher who spots a student sneaking a look at a text message may not think it’s worth stopping class discussion to call out, and confiscating phones in the classroom means taking on the extra burden of being responsible for other people’s valuables.

Spanish teacher Gerald Padilla of Marlborough High School was exasperated.

Read the full article on the Boston Globe website.