Your concerns might be different. If you have a child who doesn't get enough physical activity, maybe your rule needs to be that for every hour of screen time, you require 30 minutes of bike riding, running, or other outdoor exercise. Grades are slipping? No phone or computer until your homework has been completed and checked by a parent. Identify the problem, and figure out how you can work to correct it. Sit down with your kids to create an "acceptable use" policy for your own home—they're much more likely to follow the rules if they've had a say in writing them.
2. Use parental settings wisely
Once you set up the rules, let them be the boss, instead of you. For instance, Macs and iOS devices allow you to set usage restrictions. On a Mac, you can set Parental Controls preferences to control your kids' access to the computer and the Internet—and to specify times that they can and can't use the computer.
iPads and iPhones have fewer parental control options, but some of them can be useful. On an iOS device, launch Settings, choose General, and then choose Restrictions and tap the Enable Restrictions button. Then choose and enter a four-digit passcode—something your kids won't guess.
iOS restrictions allow you to control certain parts of the operating system—for example, to prevent your teen from installing apps or making in-app purchases. You can also set up Allowed Content for iTunes—for example, no movies rated R or NC17, or no music with explicit language. See "Set up a kid-friendly iPad" for details.
Even if you enable restrictions, however, this isn't a "set it and forget it" situation. Trust, but verify. Check up on your kids and their devices as often as you can. This may seem simple and obvious, but far too many parents don't bother to check on what their kids are doing online—and the results can be disastrous.
3. Friend your kids on social networks
At one time, I believed that parents and kids should not be friends on Facebook, but then my daughters turned into teens. Remind your kids that if they wouldn't say it at the dinner table in front of you, they shouldn't say it online. While you're at it, talk to your kids about safe social media settings.
Do they know, for example, how to ensure that only their friends can see what they've posted on Facebook? Do they understand that tweets live on in cyberspace forever? Make sure your kids understand that posting information on the Internet is akin to taking out an ad in The New York Times, playing it during halftime at the Super Bowl, and reading it over the loudspeaker during morning announcements at their school. It's highly visible, in other words—and it can never, ever be truly erased.
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