Year 12 students are encouraged to switch off social media such as Facebook and Twitter to give themselves their best chance of success in final WA Certificate of Education exams.
Adolescent psychologist and author of Surviving Year 12, Michael Carr-Gregg, said growing evidence showed that students who socialised online while doing their homework got lower grades.
A 2010 study found students' results were 20 per cent lower for social media users.
Non-users also spent on average 88 per cent longer studying outside class.
Dr Carr-Gregg said another study of NSW high school students who achieved top exam marks in 2010 found the one thing they all had in common was that they deleted their social networking accounts for the year.
He suggested students install software that allowed Facebook access at certain times or get a friend or relative to reset their password so they could not access it at all.
"Maybe they can use Facebook time as a bit of a reward for having completed some work," he said.
Presbyterian Ladies' College principal Beth Blackwood said students started a "no Facebook club" last year because it was such a big distraction.
About 70 per cent of the school's 160 Year 12s had signed up this year, installing software to block Facebook access on weekdays.
Ms Blackwood compared Year 12s to Olympic athletes who have commented on the distractions of social media.
"It's the same scenario," she said. "They are trying to achieve of their best and that technology, while it's wonderful in terms of the communication it allows, is also a distracting factor when you're not managing the time you receive it and the time you have to respond to it."
Wesley College principal David Gee said social media were a part of life and prohibition was not that effective for teenagers. Instead, the school advised students to set aside Facebook time in their study plan.
"So when they're studying, they're not toggling back and forth and only half-concentrating on study," he said. "It's about educating them to be smart users of it rather than non-users."
The WA School Curriculum and Standards Authority started using Twitter and Facebook last year to provide exam information after 90 per cent of students surveyed said they used social media.