Twitter has named former Pearson PLC Chief Executive Officer Marjorie Scardino to its board after the microblogging service faced criticism that it lacked women in its top ranks.

The news triggered an immediate positive response from Vivek Wadhwa, a former Triangle tech entrepreneur who led a vociferous campaign of criticism against Twitter for its lack of female leadership. But Wadhwa, an academic at Duke and other universities and author who now lives in Silicon Valley, wasn’t satisfied. He is an outspoken proponent for getting more females, minorities and immigrants involved in technology companies, and he made clear he wants to see more progress..

“In a nutshell, this is a great start,” Wadhwa told WRALTechWire via email from Santiago, Chile. 

“Now they need to work towards 50 percent.”

Wadhwa had been far from alone in his criticism of Twitter.

The appointment of Scardino, 66, is effective immediately, Twitter said Thursday in a filing. She led Pearson, the education and publishing company, from 1997 to last year. The addition of Scardino expands Twitter’s board to eight people.

The absence of women on Twitter’s board was “a joke,” Sallie Krawcheck, a former Bank of America Corp. executive, said last month at a Bloomberg LP conference. It showed Silicon Valley was no better than Wall Street when it came to female representation, she said. Facebook Inc., which had a similar lack of representation when it went public in May 2012, now has two female directors, including Chief Operating Officer Sheryl Sandberg.

Twitter raised $2.09 billion in an initial public offering last month, with the stock soaring 73 percent on its first day of trading. The San Francisco company has about 230 million users, who use the service to broadcast messages of no more than 140 characters. Twitter, which is unprofitable, is working to beef up its advertising business.

“There couldn’t be a more exciting time in Twitter’s history to join!” Scardino said in a post today, her first message on the service.

Jim Prosser, a spokesman for Twitter, declined to provide additional comment.Twitter has named Marjorie Scardino as a director, adding a woman to the all-white male board for which it’s been sharply criticized.

Twitter tweeted the news of Scardino’s appointment from its official account.

Scardino joins CEO Dick Costolo, Chairman Jack Dorsey, along with co-founder Evan Williams and venture capitalists such as Peter Fenton, a general partner at Benchmark Capital, on Twitter’s board.

Faced with criticism about its lack of board diversity — three of Twitter’s directors are named Peter — Costolo tweeted earlier this year that diversifying the board “has to be about more than checking a box.”

As head of Pearson, Scardino was the first woman to become CEO of a FTSE 100 company 16 years ago. The index of leading British stocks is similar to the S&P 500 in the U.S.

In her words, not much has changed in that time when it comes to gender imbalance.

Last year, she told the U.K. ‘s Telegraph that she “thought in 1997 that by the time I left Pearson things would be different in terms of how many women there were as chief executives or chairmen or board members. It’s not too different and for that I’m sorry.”