Larry Sanger, one of the founder members of Wikipedia, has launched a competitor to the online encyclopaedia. Citizendium aims to avoid the inconsistency and vandalism of Wikipedia while retaining its democratic ideals, Mr Sanger said.

Volunteer contributors to the new site will be expected to provide their real names, and experts in given fields will be asked to check articles for accuracy. Approved articles will receive a green tick to indicate their reliability.

“If there’s going to be a free encyclopaedia, I’d like there to be a better free encyclopaedia,” Mr Sanger, 38, says. “It has bothered me that I helped to get a project started, Wikipedia, that people are misusing in this way, and yet the project itself has little chance of radically improving.”

Wikipedia has faced a number of high-profile attacks on its accuracy and reliability, most of which stem from users’ ability to edit articles anonymously. Recently, it also emerged that a Wikipedia editor understood by the site and its users to be a tenured professor of religion at a private university with expertise in canon law, was in fact a 24 year old from Kentucky with no higher educational qualifications.

Stephen Ewen, an adult-education instructor in Jupiter, Florida, who stopped contributing to Wikipedia and plans to work on Citizendium, believes the quality of Wikipedia entries often degrades over time because someone inevitably comes along to express a counterproductive viewpoint.

“When you put everybody in a system that is flat, where everybody can say yes or no, without any sense of authority, what you get is tribalism,” he said. “What has gone into the article creation is very often the result of this dysfunctional system. It presents itself with this aura of authority, whereas what goes on behind the scenes is anything but.”

Wikipedia’s de facto leader, Jimmy Wales, stood by the site's format. “I am unaware of any problems with the quality of discourse on the site,” he said. “I don’t know of any higher-quality discourse anywhere.”

He denied that anonymity leads to irresponsibility, arguing that most Wikipedians who adopt pseudonyms want to protect the reputation of those names as much as they would their true identities.

There's no doubt that vandalism does pose a problem for Wikipedia. For four months during 2005, the journalist John Seigenthaler Sr. was accused of being a suspect in both Kennedy assassinations. It was removed, but for 31 hours last September a posting said that he had killed and eaten JFK.