T elevision and computers can be educational and fun... but they can take over your home if you don’t watch out.

The problem -- hour after hour of watching TV or using a computer inhibits children’s social development. The lack of exercise lays the basis for obesity. And -- studies have shown that violent TV shows and certain computer games can lead to aggressive behavior.

To keep the screen from sabotaging your family life...

Set time limits. One hour of TV a day for preschoolers and two hours for six- to 12-year-olds. Teenagers may have more time if it doesn’t interfere with schoolwork.

Monitor quality. Know what kids are watching. Make sure the programs are age-appropriate and consistent with your values.

If your child says, “But all my friends watch that,” don’t be afraid to be the mean mom or the bad dad.

Watch TV with them. Tune in to your kids’ favorite shows whenever you can, and monitor their use of the computer.

With adolescents, try to understand a show’s impact and share ideas. You might ask, “Why do you think that character did that? What would you do if you were in his/her situation?”

Be selective. Choose specific programs to watch in advance. Some families choose shows together for the coming week. Siblings can negotiate their choices to minimize squabbling. Random channel-surfing can then be avoided.

Keep TV out of the kids’ bedrooms. About 65% of eight- to 18-year-olds have TVs in their bedrooms. This is a mistake because it removes all parental control. Many parents keep computers in a central place, accessible to the whole family, so that they are not in the dark about what their kids are watching over the Internet. It’s also important to have clear, enforceable rules about the use of the computer.

Move the television far from children’s work/study area to reduce temptation and distraction. Turn off the TV during meals so it doesn’t take over family communication.

Offer alternatives. Have books, art supplies and games available for younger children.

Steer older kids toward hobbies, reading, extracurricular activities and sports. Your time is the greatest gift you can give your kids. You’ll both get much more satisfaction out of talking, walking, playing or doing a creative project than from any computer or TV program.