Three ways to get more women in tech jobs

The late Karen Spärck Jones, who was among the first women to blaze an academic trail in computer science, once quipped, "I think it's very important to get more women into computing. My slogan is: Computing is too important to be left to men." As an undergraduate at Cambridge University in the 1950s, where she initially studied history and philosophy, Jones faced high barriers to entry in a field that was almost entirely populated by men.

Much has changed in the decades since Jones switched career paths and went on to become professor of computers and information at the Cambridge Computer Laboratory, yet much remains the same.

Girls Who Code Summer Immersion Program at AppNexus.
Source: Jessica Scranton
Girls Who Code Summer Immersion Program at AppNexus.

Today, STEM jobs (science, technology, engineering and math) are a major engine of economic growth. And while women have grown their representation in STEM fields, according to the U.S. Census Bureau, they remain significantly underrepresented in engineering and computer occupations, which make up more than 80 percent of all STEM employment.

The technology sector continues to face considerable scrutiny over its lack of gender diversity, and rightfully so. But even as leading companies enact proactive measures to overcome explicit and implicit bias in hiring and promotion, they face a very real talent-pool deficit. In 1984, 37 percent of all computer-science graduates were women, but today that number is just 18 percent. Just 20 percent of AP Computer Science test-takers are female, and 0.4 percent of high school girls express interest in majoring in computer science.

Read MoreApple says it hired 65% more women in the past year

This begs the question: Why are women discouraged from pursuing careers in computer science?

The gender gap isn't just a Silicon Valley issue anymore. The shortage of women in technical roles, whether in retail, entertainment or finance, is a massive crisis both in terms of innovation and socio-economic equality throughout the United States. Fixing the problem is not only the right thing to do; it's an economic imperative.

The bad news is that there is no immediate fix; it will take time and persistence. The good news is that we are working on solutions that, if properly scaled, address the problem. We take a three-pronged approach to the issue:

Play the long game: Great technology companies want to diversify their workforce, particularly in skilled engineering and software roles. But if our collective response to the shortage of women in computer-science jobs is to start a high-stakes bidding war for the small number of eligible candidates, we are not addressing the underlying issue. Bidding wars accentuate regional disparities — favoring Silicon Valley over emerging tech corridors like Boston, New York, Philadelphia and Baltimore — and distort an already-broken labor market. They devote resources to recruiting that could be better directed to education and training. Recruiting is important. But if technology companies combine efforts and resources to grow the pool of trained computer scientists, rather than divide it up, the entire industry will benefit in the long term.

Read MoreNumber of women in tech 'disastrous': Wikipedia founder

Education is not avocation: While coding is a critical skill for work in the computer-science field, more fundamentally, it's also a way of ordering ideas. Coding conditions one's mind to consider problems and challenges creatively, much in the same way that calculus, physics, philosophy and art history impart different ways of thinking about and processing information. It's a skill that serves everyone well. The message we need to convey is not that girls (or boys) should study computer science as a narrow means to a career end – rather, that the study of computer science is intellectually exciting and stimulating in its own right. It opens the mind to new ways of thinking and problem-solving.

Mentorship matters: While there is no shortage of strong female role models in STEM fields like medical technology and health care, science education, and laboratory research, the numbers indicate a serious deficit of real-life advisors in computer science. It's not enough to tell girls that they will benefit from studying computer science. We need to show them that women can and do excel at technology roles, and we need to furnish them with the social capital that comes from early workplace interactions and networking opportunities. Doing so requires that we actually bring the girls to where the women technologists work and vice versa.

The U.S. Department of Labor projects that by 2020, there will be 1.4 million computer specialist job openings. To reach gender parity by 2020, women must fill half of these positions, or 700,000 computing jobs. Anecdotal data tells us that an average of 30 percent of those students with exposure to computer science will continue in the field. This means that 4.6 million adolescent girls will require some form of exposure to computer science education to realize gender parity in 2020.

Read MoreMeet technology's richest women

We're bullish on the long-term prospects. The girls with whom we work at summer coding programs and in high schools across the country are tomorrow's technologists and entrepreneurs. Their inquisitiveness and drive are infectious. Spend one day with these young women, and you will walk away a true believer.

Karen Spärck Jones was mostly right — computing is too important to leave only to men. Taking the long view, we look forward to the day when it no longer is.

Commentary by Reshma Saujani, CEO and founder, Girls Who Code, and Brian O'Kelley, CEO & co-founder, AppNexus. Follow them on Twitter@reshmasaujani and @bokelley.

Read MoreHow tech start-ups are closing the gender gap