When you sit down to study, the first thing you should do is to turn off all your telephones and shut off everything on your computer that could interrupt you—like Skype and Facebook.

Turn off all of your computer programs except the web browser you are using to study. Don’t worry about missing a call or a chat message. If it really matters, your friends will call you back.

This is very important because of how human memory works.

You need to review items at increasing time intervals of roughly 30 seconds, 2 minutes, 5 minutes, etc. If you are interrupted, the study value of something you have reviewed only once or twice may go back to absolute zero because you didn’t review it at the right time to convert it into a more stable memory.

For example, a phone call that lasts 10 minutes will almost totally eliminate the study value of the 10 to 15 minutes that preceded the phone call.

So turn off your phone. Turn off your chat clients like Skype or Facebook, and turn off anything else on your computer that can distract you.