SAN JOSE, Calif. — Lizzy Serrano wants to design black skateboard sneakers so cool that fellow eighth-graders would gladly fork over $40 to buy them.

Her "Half-Pipes" would feature side pockets for laces because few self-respecting middle schoolers bother to tie bows. They'd include an overstuffed foam tongue — an antidote to the complaints of hipsters who wedge tube socks into Vans and Converses to give them a fashionable puffiness.

Great idea, especially for a 12-year-old, who might make it big one day as a marketing consultant to the likes of Nike.

But behind every good product is a great deal of science. That's the point of the IBM-sponsored tech camp that Lizzy attended, similar to ones that hundreds of girls nationwide will attend this summer.

The camps expose girls to a range of technical professions — from industrial design to genetics — and encourage them to pursue degrees in science, math and engineering.

Proponents hope the girls will eventually return to the companies and narrow a growing gender gap in the male-dominated tech industry, though critics question such camps' effectiveness.

The percentage of women in the tech work force dropped to 34.9 percent in 2002 from a high of 41 percent in 1996, according to the Information Technology Association of America.

Women comprised about 47 percent of the U.S. work force in 2000, but earned just 22 percent of computer science and engineering undergraduate degrees, according to IBM research.

To counter the trend, the Girl Scouts launched a television, radio and print campaign this year. "Girls Go Tech" ads depict girls discussing math, science and technology with humorously clueless parents. The ads note that most girls begin to lose interest in math and science by about 12.

Girl Scouts Senior Vice President Sharon Hussey says efforts to get women into technical fields mirror 1960s and '70s efforts to boost the number of women in medical and law schools, where ratios of men to women now approach parity.

"We were so focused on the broad concepts of where girls are not getting involved — medicine and law — that right under our noses there was tremendous slippage happening in the computer and technology field," Hussey said.

The women engineers acting as counselors at IBM's camp in Silicon Valley also try to counter the trend.

In the Cinderella Project, counselors required Lizzy and about 50 other campers ages 11 to 13 to build shoes that fit a list of technical specifications, including foot biometrics, gait cycles and soles reinforced with prismatic cells.

"Fashion design isn't as important as construction and mechanics," said software engineer Angela Rayborn, 30, who whipped out a ruler and helped Lizzy build prisms. "You have to always measure everything. That's the only way to design things accurately."

IBM, which is expanding its 5-year-old "Excite!" program to 30 cities worldwide this summer, runs one of the best-known programs aimed at getting girls interested in technology. Hewlett-Packard, Microsoft and other technology bellwethers sponsor similar educational and mentoring programs.

Texas Instruments launched a camp this summer teaching advanced placement physics to 50 girls in Dallas. Intel's popular "Geek Chic" program places third-grade girls with mentors for several days in the chipmaker's labs and offices near Portland, Ore.

Yet because many programs strive for long-term mentoring relationships — and none guarantee results — proponents worry that corporate America, driven by quarterly earnings, might lack the patience necessary to groom kids for jobs they won't enter for a decade.

Each IBM camp costs only about $7,000, but that doesn't include the hundreds of hours per year that employees, including some senior executives, volunteer.

Kara Helander of New York-based Catalyst, which tracks women executives, worries that the camps promote professions such as engineering but don't encourage women to strive for technology's senior ranks. Women make up less than 10 percent of technology's highest echelon, by some estimates.

Many leaders of Silicon Valley's biggest companies lack technical backgrounds, including HP's Carly Fiorina, who has degrees in business, medieval history and philosophy.

Camps should encourage higher education in all disciplines, said Helander, whose organization tracks 75 tech executives in 29 companies.

"Having a technical degree is not a prerequisite for success in high tech," she said. "These programs are generating attention on science and math, but you can't draw a direct line from them to women in senior positions in the tech industry."

But closing the gender gap in the U.S. tech sector will have little effect on what is a more disturbing trend to many: America's liberal arts-based education system prevents the country from producing proportionately as many scientists as Russia, India or China.

That could end U.S. dominance in technology, warns John Yochelson, president of San Diego-based Building Engineering & Science Talent, a public-private partnership that helps companies hire and promote women and minorities.

"The camps represent bright spots in a larger picture that is not so positive," Yochelson said. "We're dealing with a very profound issue, and we won't get to where we want to go as a nation unless there are fundamental changes in the workplace, at colleges and universities and down to elementary school."