WORTH NOTING ON TV

* THURSDAY

Family Theater (CBS, 8:30-9 p.m.): "The Magic Paintbrush" is an animated version of an award-winning book written and illustrated by Robin Muller. A boy named Nib helps an old man and in return gets a paintbrush that can bring the boy's paintings alive. The fairy tale may not really require a TV version, but since it will air during National Library Week, the production does serve to bring attention to the book and to reading in general. That's the aim of the show's sponsor, McDonald's, and during commer cial breaks, Ronald McDonald will talk about reading and try to instill in young viewers a desire to visit local libraries. If Ronald's presence also happens to instill a desire to visit a certain fast-food restaurant - well, he can't help that, can he? * FRIDAY

America's Education Revolution: A Report From the Front (PBS, 9-10 p.m.): On the 10th anniversary of "A Nation at Risk" - the renowned and controversial report that described a failing school system in the United States - this documentary takes a look at educational reform efforts around the country. It focuses on four cases that illustrate what happens when people set out to change their schools - the challenges faced, the tactics used, the progress achieved. Not surprisingly, politics turns out to play

a part in successful reform and often money does, too. Thomas Kean, president of Drew University and former governor of New Jersey, is the narrator and reports on location.

Time Machine (A&E network, 8-9 p.m.): Lots of kids - and more adults than will admit it - once flocked to local movie houses on Saturday morning to see the "serials." The previous Saturday, their heroes had been left dangling from cliffs or maybe tied up and moving toward a buzz saw, and fans just had to learn what happened next. "Cliffhangers: Adventures From the Thrill Factory" rediscovers this popular form of the 1930s and '40s as it offers selective reels from the archives of Republic Pictures, purve yors of some of the most hair-raising examples of the genre.

Please check local listings for all programs, especially those on PBS.