Sheryl Sandberg likes to ask a question when she speaks publicly, and she uses it to illustrate the gender bias she believes is laced through career and life in America and the world.

"For the men who are here, please raise your hand if you've been told you're too aggressive at work," she told a crowd of mostly technology-industry women in Minneapolis on Wednesday.

Very few men ever raise their hands on that question, said Sandberg, the Facebook executive who sparked a nationwide discussion of gender and careers with the March release of her bestselling book "Lean In."

But when she asked how many women had been accused of excessive aggression, hundreds of hands shot up.

"That's true all over the world," Sandberg said. "Everywhere in the world, we expect men to be leaders, to make decisions. Everywhere in the world, we expect women to speak when spoken to, to not be as strong, to give to others."

Sandberg was in downtown Minneapolis for the Grace Hopper Celebration of Women in Computing, which has attracted 4,600 people from around the country and runs through Saturday.

A who's who of tech world

Representatives from such companies as Google, Amazon and Microsoft are attending, and the conference has a who's who of corporate sponsors. Attendees include 1,600 college students, nearly all of them women looking to network and propel their careers in technology.

Held in a different city each year, the event was founded in 1994 and named after early computer scientist and Navy Rear Adm. Grace Hopper, who among other things helped lay the groundwork for COBOL, a programming language still in use today.

But Sandberg said the progress of women in business, and particularly in technology, has flatlined. Men are more often rewarded for showing initiative, she said, women more often subtly punished.

Both are guilty of harboring this bias, and the problem is powerfully self-perpetuating, said the author of "Lean In: Women, Work and the Will to Lead," who has since launched a campaign encouraging women to be more ambitious and assertive.

Men run 95 percent of the big companies in the world, Sandberg said, and men hold three-quarters of the jobs in computing and information technology.

Meanwhile, women too often hold back. They underestimate themselves, she said, don't ask for promotions as readily, don't push for raises and, in technology, there is simply not enough female participation.

"I don't think that's OK," Sandberg said. "I think we can and will do better when we use the full talents of our population in every industry, in the technical industries that are so critical to our future."

High-tech has high stakes

Sandberg sat for a keynote conversation with conference co-founder Telle Whitney and Maria Klawe, president of Harvey Mudd College in California.

While the number of jobs that require high-tech skills has grown dramatically over the past few decades, the share of women preparing for those jobs has plummeted. Thirty-seven percent of computing degrees went to women in 1985, compared with 18 percent in 2009, according to the National Center for Women and Information Technology.

Whitney said the number of women getting computer science degrees started to fall when the field was rolled into college engineering departments. People had less sense of what could be accomplished with a computer science degree in the 1980s, and boys latched onto personal computers and video games more quickly than girls. While the share of computer science degrees going to women rose in the 1990s, the percentage fell again after the dot-com bust.

"There was a view that the jobs were being outsourced, and also it just wasn't cool," Whitney said. "There's an image factor that's probably the biggest issue."

At Klawe's college, nearly half of sophomores who declared computer science as their majors are women. She said the key is to make computer science fun and accessible. High school girls, Klawe said, think that programming is boring, that they won't be good at it because computers are daunting and that they "wouldn't want to be seen dead with the people who work in computer science."

So Harvey Mudd started sending first-year female students interested in computer science to the Hopper conference, to introduce them to the world of women in technology. The school retooled its computer science curriculum to make it more interesting and fun.

"They took the introductory computer science course, and they just decided to make it the most fun course you could possibly take," Klawe said. "They made it not scary."

Sandberg said technology is driving progress in the world and allowing unprecedented new types of collaboration, which only adds to the urgent need for female participation.

Before the Internet, the largest project that a large group of people worked on together was a pyramid, she said, and that was about 70,000 people. In 2009, Facebook announced that 300,000 people had helped translate Facebook into 70 languages.

"Technology is going to change the world," Sandberg said. "In order to change the world in the right ways, we need women to lead along with men."

Adam Belz • 612-673-4405 Twitter: @adambelz