NEWBURYPORT, MASS. — Lizzie Stokes leans over the desk. Through the round red-framed glasses perched on her tiny nose, she peers at Katy, a cartoon character she's just created. Katy is tall and lanky and has long blond hair. But she wears no clothes, until Lizzie chooses from a variety of spotted, striped, and plaid clothing and, after some lip-chewing thought, clicks a snazzy virtual jacket onto Katy. Lizzie is playing with "Rockett's Adventure Maker," one of the latest entries in Purple Moon's Rockett software series, and one of the newest products in the fast-growing category of software designed for girls. Purple Moon's main character, spunky preteen Rockett Movado, could be one key to the solution of a gender-equity problem. In a report last October, the American Association of University Women stated that girls take fewer advanced computer-science classes than do boys and use computers less often at home. And they're far more likely than boys to take data-entry courses, what the AAUW calls "the 1990s version of typing." As a result, the group says, girls are less likely to be interested in nontraditional careers, like engineering and environmental science. Part of the trouble, the AAUW says, is that, because boys play computer games and use computers at home more than girls do, boys enter the classroom more comfortable with computers. Brenda Laurel agrees. Ms. Laurel is Rockett's inventor, and the founder and design vice president of Purple Moon, in Mountain View, Calif. But she disagrees with the widely held view that girls don't like computers. She says girls are happy to play with computers, as long as the software appeals to their interests. And their interests, she says, are fundamentally different from boys'. For 22 years, Laurel's been designing computer games, primarily for boys. She didn't intend to ignore girls, but publishers of video games - who are almost exclusively male - turned down many of her ideas. One was about "spirit animals," where the player becomes a bird, snake, or mouse to solve a problem or go on a journey. "I didn't know why [they were turned down]," she says, "until I met David Liddle and did this research and learned why: I was having girl ideas." David Liddle, co-founder of Interval Research, a Silicon Valley venture-capital firm, was as interested as Laurel in the reasons girls didn't play computer games and publishers didn't market to them. As well as being intrigued by this untapped market, both were concerned with research that showed that sixth-grade girls, if they hadn't already used computers, were at risk of shying away from science and technology permanently. Mr. Liddle hired Laurel in 1992 and they began a multimillion-dollar research project that explored gender, play, and technology. They read hundreds of research papers; interviewed experts; and talked to parents, coaches, and 1,100 children. They learned, Laurel says, that girls and boys organize themselves socially in fundamentally different ways. Boys are more likely to use overt competition (bopping an opponent on the head) to acquire power, for example. Girls are more likely to compete covertly, acquiring power by affiliating with or excluding other girls. They also learned that girls found computer games boring because typical superhero characters weren't complex enough. Girls, it turned out, like characters with whom they can imagine having relationships. Says Laurel, "Boys are interested in what a character does. Girls are interested in why a character does it." Laurel and Liddle also examined the ways kids decide whether a toy is for a boy or a girl. "We learned that pinkness overrides toughness every time," the wry Laurel says. "No amount of bullet holes make a boy want a diary, and nobody wants a Barbie doll in GI Joe's clothing." In 1996, using the research as her basis for design, Laurel spun Purple Moon out of Interval and began creating the Rockett series. Most of the games appeal to preteen girls by providing elaborate story lines and engaging them in the emotional lives of the characters. So far, the company has achieved moderate success; International Development Group (IDG), a toy-industry researcher in San Francisco, pegs Purple Moon's 1998 revenues at more than $4 million. But the category itself has skyrocketed, from $2 million in 1995 to $149 million last year, with about 60 titles on the market by year's end, according to IDG. Still, the question remains: Can games for girls help narrow the gender gap? Laurel says researchers don't have enough data to know. But, she says, "We think this will create comfort and that girls will see computers as a medium that delivers engaging experiences. That takes all the fear away so that it's no longer a technological object, it's a medium, just like a telephone or a TV." That doesn't necessarily mean that parents should rush out and buy girl-game software, at least according to Lizzie Stokes's mother, Nan Appleyard, a former high school English teacher. She is unimpressed with "Rockett's Adventure Maker." Though Lizzie is enthralled, Ms. Appleyard says the software provides few opportunities for original thinking. Lizzie can create characters by choosing from a handful of body types, hairstyles, and skin colors, but she can't draw characters from scratch. Other questions arise from those who argue that the gender gap is not very significant. Linda Roberts, special adviser on technology to the secretary of Education, agrees that girls don't enroll in computer classes at the rate that boys do. But, she claims, girls are doing more with computers than they were 10 years ago, when she first began visiting classrooms. Now, she says, "I have been in schools where [both] girls and boys are building the networks and designing the Web pages." But women remain underrepresented in high-tech careers - a problem that concerns the AAUW. As a result, some women in technical careers are eager for software or any other intervention that will increase girls' interest in physics, engineering, and other nontraditional career. Denise Nicoletti, an associate professor at Worcester (Mass.) Polytechnic Institute, teaches electrical engineering. Only 15 percent of her students are women. She welcomes nonviolent software for girls: "It may attract women; it may attract men who are turned off by war games. Technical careers fly with diversity, so if different groups of people are coming into the careers then technology is only going to get better."