Wikipedia founder Jimmy Wales has launched a recruitment drive for women because its team of "26-year-old geeky, male" contributors lack the expertise to edit some of its pages.

While the internet encyclopedia is "very strong" in some areas, such as science and technology, he said, its coverage of other issues was suffering because of a lack of diversity within its community of editors. "The main thing is to bring in people of all different backgrounds. If you do that, you increase the knowledge base of the site, which can only be a good thing. At the moment, we are relatively poor in a few areas; for example, biographies of famous women through history and issues surrounding early childcare."

He said that research the company had done suggested that nine in 10 of its contributors are male and that the average age was 26. A higher percentage of them hold PhDs than does the public "so I don't think they'd mind me calling them geeks", he added. Mr Wales revealed that he plans to double the number of people actively editing the site's pages within a year. He admitted the site is currently losing editors but added that the rate with which they were leaving had been exaggerated.

In June 2010, the site had a little more than 36,000 writers, he said. By June this year, that number had fallen to 35,800. He scotched suggestions that the figures mean the site is "in trouble", saying that "the current number of contributors is stable and sustainable". But he said that he would like to increase it in a bid to improve Wikipedia's accuracy and reach.

Mr Wales set up Wikipedia in 2001. The site's writers are all unpaid and he has no plans to change that system.