Ali McGraw is earnest. "Let's face it," she says, "they're using me." She is talking to two Channel 5 talk show hosts who think the public will want to know why Ms. McGraw --now a stylish 40 and a veteran of several box office disasters--is here in Boston publicly plugging VISTA (Volunteers in Service to America, known in the trade as "the domestic Peace Corps"). "The people from VISTA have really impressed me with--gosh, I don't know how to say this--their social awareness, their desire to make the world a better place."

The hosts nod, murmur "Mmm, yes, oh really," then cut to a commercial--and the band strikes up the theme from Love Story.

Eyes sagging from jet lag, but still perky and extremely sincere, McGraw will repeatedly deliver the "social awareness" line throughout the day. Every reporter and television host is suspicious of her motives for doing unpaid yeoman service to an organization that seemingly disappeared from view after the Sixties. If interviews press her--the hostess on Channel 56 asked McGraw redoubles her sincerity and comes up with creative variations on the original explanation: "It's an awareness campaign--you can really change the quality of life in America," or "It's not about raising money. It's about taking control of our lives.

But this isn't what the television audience wants to hear about. Channel 5's host guides the discussion back toward the really important issues in her life. How does she stay so young? ("I've begun to realize we are what our bodies are") and, How does it feel to be 40? ("I've realized all the good stuff is ahead"). Cut to commercial and that familiar Love Story theme.

This Keeps up all day. Images of the Movie prevail during her visit and she admits that it still haunts her career. She is stunned that Harvard students still show the film as a freshman week tradition. "I haven't seen it in ten years. It's so far from my reality now," she says. "I just don't take it seriously anymore, though, let's face it, it changed my career." But as much as McGraw breathlessly exonerates herself from the movie, Jenny Cavilleri is grafted onto her. She knows this. Yet she can't understand why people "in the most obscure corners of the globe" come up to her in the street and relate to her as the baker's daughter from Providence who died in Ryan O'Neal's arms,

It's the voice. Very earnest.

"That's not the way it's going to be, Ollie."

"Use your own library, preppie."

And today: "Most of the conversation is yours, I really mean it." She is talking to Marjory Tabankin, national director of VISTA, who is also trying hard to sell the idea of VISTA to the public. Unlike McGraw, she understands the organization and how it works; McGraw is simply one of the 50-odd "celebrities" asked by VISTA to do day-long publicity stints.

"I'm not claiming to be more informed than I am," McGraw says after failing to explain VISTA's functions to yet another interviewer. This was suposed to be a "day of education" for her, but somehow she ended up going straight to work, traipsing from TV station to TV station, interviewer to interviewer. Every chance she gets she tries to get educated, sitting there listening, head tilted, lips pursed, trying to understand.

"I'm stupid about politics," she says, explaining why she isn't as active as her colleagues Jane and Warren. She'd rather sponsor activities more directly applicable to families and children. Cambodian aid, for example. Why? "It's easy to get behind it and relate it to my life, you know," she explains.

McGraw splits her time between the waves at Malibu and the concrete canyons of New York, where she "must be because I need it culturally and spiritually." This is the still of People magazine, but she hesitates to dish it out. A Newsweek "newsmaker" reporter presses McGraw on her future plans. She smiles and dodges the question. Her average day? There is none. When the reporter continues to lunge for the definitive statement, the quotable quote, McGraw smiles and whispers, "I'm just living my life now." Her earnestness is infectious and everyone smiles. In fact, McGraw leaves a trail of fans wherever she goes. As she leaves Channel 56, secretaries clutter around for signatures and as she writes our her name on someone's napkin, she asks one woman what kind of perfume she is wearing and another where she got her arm's length of bracelets. McGraw even consents to posing for a photograph with a man who "wants to drive his wife nuts." She says she doesn't enjoy it but realizes its part of the job. A real trooper. But the caravan is rolling and she enters the waiting van for the next appointment.

McGraw's silver screen appeal doesn't thrill the VISTA people, who wish she and reporters would stick to the issue--their promo campaign. Their prayers are answered when the van pulls off the highway in the South End and parks in front of a VISTA-run refuge for battered women. Tabankin is here to find out how well the VISTA program is working. McGraw is here to learn. As reporters look on, she speaks with the organizer of the home for a few minutes, and the first time she raises her voice above a whisper it is to ask, aghast, "Do these men really stay in these women's lives?" She is horrified.

Some people from Boston University filming the home try to act unruffled by the movie star's presence. Certainly the women at the home are unmoved. The VISTA volunteers calmly ask all the men to leave (except the filmmakers) and begin their scheduled discussion on battered women. A battered wife speaks for some time, describing her experiences. Her account is followed by several others. All these women have been beaten, McGraw realizes, horror slowly registering on her Pacific-tanned face as she discretely twists her necklace around so the diamond doesn't show.

As the meeting drags on, her face settles into a grimace of earnest concern. But Hollywood returns once the meeting ends, and she responds to one filmmaker's "How you doing?" with all the warmth of a close friend, looking straight into his eyes and smiling. The voice returns. "Gosh, can you believe it?" And then, very seriously, "I think it's great that VISTA is helping these women out. I'm knocked out by the kind of work that's being done."

She turns, smiles for a photograph, offers half her sandwich to a reporter, and heads for the old age home across town.

Images of 'Love Story' prevail during her visit, and she admits it still haunts her career. It's the voice. Very earnest.