Summer camp has changed.

According to ads crowding the back pages of Sunday magazine supplements, camp has become a no-nonsense, problem-solving place. Dutiful children are sent to lose weight, play competitive tennis, learn French, or undergo some other type of self-improvement.

And if the ad copy is to be believed, parents who choose these camps can be proud that their kids are not wasting summer vacations in idle recreation.

Even samples of campers' letters are included -- testifying to the wisdom of the family's investment:Dear Aunt Ariadne,

Speed Reading Camp is real neat. Now I read 10 times faster and remember practically everything. This morning I read The Brothers Karamazov, Moby Dick and Hollywood Wives. I especially liked the part where Dimitri learns the truth about Capt. Ahab and Mrs. David O. Selznick.

Thanks for your nice long letter. I read it in 14 seconds. Love, Lisa Dear Mom,

Getoutta-My-Way, the Camp for Timid Kids, is okay, I guess. The staff here teaches us lots of assertiveness skills. Yesterday we learned how to cash a check without identification.

Every day the counselors help us increase our I.Q. -- that's our Intimidation Quotient -- by adding a new sentence to our "power vocabulary." Yesterday, it was "Let me speak to your supervisor!" Today's phrase is "What do you MEAN you can't find my reservation?"

Next week we're taking a shopping trip to New York City. Every camper has to buy something at Macy's and then have it returned for a full refund at Gimbel's.

Anyway, I think I'm becoming more assertive. My junior counselor told me so. Love, Janice Hey Sis!

Big Time Sports Camp is all right! Even though we don't do athletics here, we learn everything we need to make it in the pros someday.

Each morning we split up into groups. Today the baseball guys had a session called "Lifetime Contracts: How to Spend $40 Million." The tennis players took a seminar on Advanced Racquet Abuse. And the hockey players saw a film on cosmetic dentistry.

After lunch a pro basketball star gave a clinic on endorsements. This guy is a real pioneer. He was the first player in NBA history to sell the sneaker rights to each foot separately.

Tonight is NCAA Night, and we have to attend a lecture on the responsibilities of the college student-athlete. That probably means a sermon on either drugs or gambling. I got $50 at eight to five on gambling. See ya, Wayne Dear Grandma,

Your correspondent is reporting from the Junior Investigative Journalists camp. Weather has been good, according to reliable sources.

When I filed my last dispatch with you, I was stuck on the food beat of the camp newspaper. But that was before my expose' on the camp's famous "pot luck" supper made Page One.

Now I've moved up to the Broadcast Media Cabin. Every morning we stage our own version of "The Today Show," which is a lot of fun except when I have to be Willard Scott.

More later on these and other developments, Love, Mark Dear Dad,

Camp White Lie is really fun. And I've stopped telling so many whoppers, honest!

The counselors keep telling us honesty is the key for a successful career. Everybody can't be a defense contractor. And unless you can pass a lie detector test, you can't even work at the Pentagon.

Some of the campers here are a lot worse than I am -- especially Stan, my cabinmate. At lunch today one kid bragged that his dad owns a TV station and manages a Little League team. So right away Stan claims his dad is Ted Turner. What a liar! But I put him in his place.

Sorry I didn't write sooner, but a big lion came and ate all my stamps. (Just kidding!) Love, Timmy P.S. By the way, Dad, just for laughs, would you mind signing your next letter "Rupert Murdoch?" Dear Mom and Dad,

This camp stinks! There's nothing to do here -- just archery, hiking, swimming, canoeing and a lot of other useless stuff that never helped anybody attain financial security.

Next summer can I go to Cloutward Bound, the survivalist camp for future corporate leaders? There the kids learn how to build tax shelters and how to light fires under a staff by rubbing two junior executives together.

I know you both loved Camp Lockjaw, but please don't make me waste another summer here. I hate to break it to you, but there's just no money in learning to make lanyards.

Can we take a lunch on this when I get back in town? Best Regards, J. P.