Q.We are the parents of two teen-agers: a girl, 14, and a boy, 16. Both are well-behaved and obedient children and a joy to us.

Our question is about the use of the telephone.

It's suddenly become very important for our daughter to use the phone a lot, with conversations revolving around the rehashing of the day's activities with several of the others in her group. I can truly see the necessity of this support at this age, but need some guidelines about how much use the phone should receive. Should it involve minutes per hour; number of calls; total time allowed per day, etc.?

We decided not to let her have her own phone, which she was willing to pay for, because we were concerned that this would encourage the use of the phone even more.A.Your daughter is networking and the need is nothing new.

Once it was satisfied by quilting bees or visits over the back fence -- a custom and a need that must go back to a far more primitive time. Who'd want to be stuck all alone with a baby in a cave?

Teen-age boys need to forge links too, but because they're so competitive, they do it with activities far more than words. It may be soccer or some complicated pursuit like Dungeons and Dragons, but talk for talk's sake is secondary.

This is not true for teen-age girls. They talk on the telephone -- and anywhere else they can -- and it's the talk and not the activity that often matters most. It isn't just silly conversation or gossip they're exchanging -- although there's usually some of that -- but a sense of security. Each gives a measure of trust to the other, and so gets more trust in return.

Instinctively they seem to know it takes a day-to-day rehashing of events for them to understand their friends and eventually themselves.

The telephone also gives them the privacy to talk about things that might be embarrassing to mention face-to-face. This is always easier when they don't have to make eye contact -- in the dark or in a car or on the phone.

This doesn't mean, however, that your daughter's need for the telephone gives her the right to use it whenever she wants, nor would it be wise for her to have her own telephone. When a family does need two lines, it's better for parents to have the use of both of them, and children to be restricted to one. It's a subtle way to help children keep their sense of importance in perspective.

If your daughter did have her own phone she would surely use it more than she uses the family phone now, and it would be harder for you to set limits, especially if she were paying for it. It also could isolate her. When a child has her own telephone (or her own television or her own car), she has fewer chances to learn how to negotiate, to compromise, to cooperate.

Your daughter must learn to share not only the phone but also herself. To do it she needs rules but let them be as few as possible. Drawing lines in the dust only invites a child to cross them, just to proclaim her independence. Instead let your rules be as general as possible -- and sometimes look the other way when she breaks them. A few more minutes or an extra call isn't such a big deal.

You might let your daughter use the telephone between the time she comes home from school and dinner and for as much as a half-hour out of every hour if it doesn't interfere with her chores or with the use of the phone by others.

You'll put the phone off-limits during dinner, of course, and probably set a stricter schedule afterwards, with no incoming or outgoing calls during homework time; no calls lasting more than 15-20 minutes and none made or received after 10 p.m.

You also may decide your daughter can use the phone longer if you have an interrupter service, to know if someone has a call waiting, or to let her pay for the service if you don't have it, so she can talk a little longer.

Through all of this, you want to teach your daughter to be sensitive to any impatience she notices in others when she's on the phone. Help her realize that if she is quick to get off the phone when someone else is waiting to use it, you won't have to tighten your rules. Even so, you can expect a scheduling problem if your son becomes a phoner too, which often happens when a boy of 16 or 17 gets a girl.

That's why you'll want to teach both children to be generous before the phone becomes a point of conflict.

Home is where they sharpen their sense of give and take -- especially the giving part. This is the essence of good manners -- of kindness and consideration that makes a family get along. A telephone can be a good teaching tool, as long as you're the teacher.