Former Pearson CEO Marjorie Scardino joins the Board of Directors of Twitter as its first female director. Scardino was the first woman to become CEO of a FTSE 100 company in the UK when she was appointed head of Pearson in 1997. Her reflection on the progress since then is one of disappointment. She told the Telegraph newspaper when she left Pearson that not much had changed in the 16 years since 1997, with few women on the board of directors, chairmen or CEO positions in the corporate world. Yoree Koh points out in this report that only 8.4% of Silicon Valley companies have women directors, according to an annual study put out in Dec. 2012 by the Universiy of California, Davis. About 40% of the tech companies in the S&P Composite 1500 index have no women on their boards, according to an Ernst & Young report.