Melissa Joan Hart says when she was 4, she wanted to become an actress so she could hear her own name on television.

"I said I wanted to be on `Romper Room' because I really wanted my name said in the Magic Mirror, and I knew there was no way to do that unless I was on the show because she would not say Melissa," Hart said. "So I figured if I was on the show there's no way she could get around it, she'd have to say my name."

Now she hears her name all the time -- Melissa, star of "Sabrina, the Teenage Witch" on ABC; Melissa, co-star of the network's new kid show, "Sabrina, the Animated Series"; and now Melissa, star of "Drive Me Crazy," a romantic comedy that hit theaters Friday.

And there are behind-the-scenes beckonings as well: Melissa, an executive producer of the prime-time series; Melissa, a partner with her mother, Paula, in Hartbreak Films; Melissa, the big sister and mentor to seven siblings, all of whom have worked in the business.

These days the 23-year-old former star of the Nickelodeon series "Clarissa Explains It All" is spread thinner than fat-free cream cheese on a supermodel's Melba toast.

She's bouncing between coasts to promote the movie, wedging in press interviews between talk show appearances while her publicist keeps a close eye on the itinerary and his watch. She fights back yawns of fatigue and reminds herself that she needs to telephone a professor at New York University to ask for a year's leave of absence from her bachelor of arts correspondence program. She'd love to keep up the studies, but there just isn't time.

The degree in progress, begun in January 1994, is not precisely defined yet -- "some kind of combination of art and literature," Hart said, rattling off a wide range of classes she already has completed. When will she graduate?

"I'm hoping in the next four or five years," she said.

Paula Hart said her daughter is very hands-on as vice president of Hartbreak, keeping involved with 43 projects in development and using her celebrity stature to open doors with stars she would like to cast and with studio chiefs.

"When she was little, she worked constantly," Paula Hart said. "I found that when she was working, all of her school grades were straight A. But when she would take a break, all her grades would drop.

"The more pressure she has on her, the better she does. She's one of those Type A personalities, I guess."

Originally titled "Next to You," "Drive Me Crazy" centers on Nicole (Hart), a fun-loving high school senior intent on saving face with the popular crowd after the school basketball star jilts her. Her neighbor, Chase (Adrian Grenier), is a social outcast by choice who wants to get back together with his girlfriend and agrees to "date" Nicole to make their exes jealous and win them back.

Hart said the fact that Grenier and she are so different -- he's the quiet, keep-'em-guessing counterpoint to her high-energy effervescence -- was a big plus during the shoot. (Despite a well-publicized "thing" they had during filming, she did not mention Grenier or any other man when pressed about her love life.)

"We're very much like our characters, and yet we get along very much like our characters," she said. "We really have a great relationship because we're very open to listening to the other person about what their opinions are, about what their views are on something. We really respect each other, basically, is where it all comes from. We respect that we kind of come from similar places but take different approaches to things.

"He actually explains it a lot better than I do," she added.

The role, which calls for Hart to appear manipulative and, in one long scene, smashed, represents a baby step toward playing less-wholesome characters than Clarissa and Sabrina.

Paula Hart is no Mama Rose aiming to keep her daughter in the Dainty June costume as long as possible. In fact, she has been propelling Melissa toward more sophisticated projects. In some recent publicity photos, the actress turns down that high-wattage smile for a more sultry look, camouflages her girlish freckles, tousles her blond mane into bedroom hair and flaunts her navel ring.

Just the same, don't look for Melissa Hart to plunge immediately into deeper, darker waters.

"There are so many things I'd like to do, but I know I'm not ready for them yet," Hart said. "The next step for me would have to be something a little bit more serious, but not too serious, not melodramatic. A character that has dimension, that's real, that's going through some kind of change, some challenge. It's hard to say, but if I read it I'd know."

Hart enjoys nightclubbing and partying with close friends at her Hollywood Hills home, but she remains mindful as ever of public expectations of a celebrity branded as the girl-next-door type.

"When you are in the public eye, there is certain responsibility," she said. "You have to walk a fine line about how far do you go with your own life and then how far do you take the role model thing. When do you start to do your own thing and just live your own life?"

Hart reflected back to 1997 when, during her first season of "Sabrina," she felt ill at ease playing some of the screwball bits the scripts demanded. "Now that's what I love is all the over-the-top stuff. Maybe it's because I'm so comfortable now after four years of working with the crew and I know everybody so well.

"If I ever tried to do anything serious in front of those people, they'd laugh at me. They just know how goofy I am, and we all have so much fun being idiots together."

Really, she said, her "Sabrina" friends would be very supportive of any endeavor. "But I just feel stupid acting in front of them. If anyone could see right through it, it would be them." A pause. "So maybe it would be good to do it in front of them because it would put me to the test, make me work my hardest."