The report by Dr Felipe Ortega, a research scientist with Madrid's Universidad Rey Juan Carlos, was published in the Wall Street Journal on 26 November. It reported a ten-fold increase in the number of editors leaving Wikipedia at the beginning of 2009 compared to the number in the equivalent period of 2008.

Wikipedia is open to contributions and relies entirely on volunteer contributors (editors), who create content, check the facts, correct errors and refine the entries in the online encyclopedia. Editors can contribute anonymously or can open a free account and become logged editors.

The finding in the November report follows a detailed analysis over three years that Dr Ortega carried out for his doctoral thesis on Wikipedia. The thesis analyzed the complete history of changes made to Wikipedia by logged editors for the top ten language Wikipedias. Data analysis was speeded up by using a specially-written program called WikiXRay.

The results of that study showed a leveling off in the number of contributions and revisions made by logged editors in 2007-8. The numbers of new editors and those becoming inactive followed each other closely until the summer of 2006, when in all language editions the rate of those leaving overtook the rate of those joining for the first time. There was also a growing inequality in contributions becoming more biased towards a core of very active editors.

In the latest study Dr Ortega found a continuing decline, with a net loss of 49,000 editors in early 2009, but only 4,900 in the same period in 2008. The report suggested that recent changes aimed at improving the quality and accuracy of the site contents and reducing vandalism have meant a core group of volunteers now approves pages contributed or edited by new editors, and this slows down the process of getting the content on site. It also means more work is carried out by a decreasing number of highly active editors.

The Wikimedia Foundation responded to the latest report saying it was inaccurate and the number of editors is stable, but Wikimedia counts only those who have made five or more contributions, while Dr Ortega counts those who have made one or more. This means Wikimedia's number of editors is around one million, while Ortega's number is approximately three million.

Wikimedia Foundation's Deputy Director Erik Moeller, said the numbers of editors contributing to Wikipedia peaked in 2007, and then declined slightly, and have now stabilized. Wikipedia's co-founder Jimmy Wales also said the number of editors was stable, and there had been no alarming decline. Wales said a leveling off in the number of contributors was expected because you "can't keep growing forever."

Wikipedia was started in 2001 as an experiment, and is now one of the top most popular sites on the Internet.

© 2009 PhysOrg.com