Google's first diversity report, published last month, showed that women occupy only 21% of leadership positions and 17% of tech jobs at the company. Google has no female executive officers, and only one woman on its senior leadership team.
Yahoo -- led by CEO Marissa Mayer -- released a similar report on Tuesday, revealing that 23% of people in vice president roles or higher were female.
When Twitter(TWTR, Tech30) filed for its IPO in 2013, it did not have a single female investor or board member. It had only one female executive officer, and she had been hired just weeks earlier. (The company has since added publishing executive Marjorie Scardino to its board.)
The true scale of Silicon Valley's problem is difficult to determine, largely because most major tech companies closely guard their data.
Starting in 2011, CNNMoney probed 20 of the most influential U.S. tech firms. Almost all refused to provide numbers on workplace diversity.
Data collected on five companies -- Cisco(CSCO, Tech30), Intel(INTC, Tech30), Dell, eBay(EBAY, Tech30) and Ingram Micro(IM) -- showed a significant gender imbalance in officer and management positions. Intel had the lowest percentage (14.6%) of women in those roles, while Dell had the highest (21.6%).