For years, ABC's Friday-night sitcoms have been labeled ''baby-sitter comedies.'' Stocked with cute kids, throwaway wisecracks, and happy endings, they keep young viewers company while their parents are out, without attracting many smiles from grown-ups, critics, or Emmy voters. But lately, ABC has been laughing all the way to the top of the ratings. Family Matters, which couldn't crack Nielsen's top 30 last season, has soared to 16th place for the year on the wings of nerdy Steve Urkel; Full House, in its fourth season, has also moved into the top 20; and, at an age when most sitcoms start to fade, the six-year-old Perfect Strangers has actually gained viewers. And the shows may not have peaked: In 1991, Full House and Family Matters have passed NBC's The Cosby Show and A Different World to become the most popular hour of comedy on TV, drawing nearly 60 percent of viewers under the age of 18.
ABC Entertainment executive vice president Ted Harbert, who shepherds the network's comedy lineup, credits the Friday shows all of which are produced by the team of Thomas L. Miller and Robert L. Boyett with keeping ABC in the ratings race. ''In terms of its importance to the network, I think it's reached the level of (NBC's) Thursday lineup,'' he says. So when Going Places, the night's newest entry and a show with less kid appeal than the others, lagged in the ratings earlier this season, ABC went to Miller and Boyett and suggested they add some preteen cast members and plot lines. It worked; before Going Places went on temporary hiatus March 8, the show rose sharply in the ratings, finishing in 34th place after starting the season as No. 50. In its place, ABC is now testing Baby Talk, a show that Harbert admits ''has had a rough birth,'' but whose infant star, he says, ''fits perfectly into the Friday framework.''
In May, ABC will have to decide whether to break up a very successful act by moving Family Matters to another night next season, where Harbert feels it could anchor an entire evening's shows. ''It's the toughest call we have to make,'' he says. ''But there's a real lesson here. From 8 to 9, the key to life is getting kids to watch. Because eventually, they bring their moms.''