THE largest encyclopaedia in the world has promised to change its editorial policy after running an article that wrongly accused a retired 78-year-old newspaper editor of being directly involved in the Kennedy assassinations.

John Seigenthaler, the former Editor of The Tennessean, in Nashville, and the father of a prominent NBC television news presenter, found himself unable to sue because the encyclopaedia, Wikipedia, operates online as an collator of information.

That makes it a service provider, such as a telephone company, rather than a publisher, such as The Times.

Wikipedia, often billed as the next Google in the American press because of its vast influence over the flow of information, was founded as a nonprofit enterprise in 2001 by Jimmy Wales, 39, a former Wall Street trader from Alabama. Its body of knowledge comprises articles posted by members of the public on subjects as diverse as cupcakes and neurosurgery.

Mr Wales said that the Seigenthaler affair had prompted him to ban contributions from unregistered users, although critics point out that registration takes only a few seconds. Wikipedia has a team of 600 volunteers who review facts.

“What we’re hopeful to see is that by slowing that down to 1,500 [article postings] a day from several thousand, the people who are monitoring this will have more ability to improve the quality,” he said. “In many cases the types of things we see going on are impulse vandalism.”

Many bloggers were less supportive of Mr Seigenthaler, saying that he could have simply corrected the article himself. Others pointed out that even the Encyclopaedia Britannica contained errors, some of which were recently discovered by a 12-year-old boy.

The growth of Wikipedia has threatened to render traditional encyclopaedias obsolete. Within four years it has amassed two million articles, in multiple languages, that grow in number by 7 per cent a month. As of November, the encyclopaedia was serving a staggering 2.5 billion pages a month. But the convenience of the service has made users reluctant to question the accuracy of the articles — or the motives of the contributors.

Until now. Before going public with his outrage, Mr Seigenthaler, who worked on John F. Kennedy’s 1960 presidential campaign and was a pallbearer at his funeral, attempted to identify the person who had posted the article about him. It included a now infamous line: “Was thought to have been directly involved in the Kennedy assassinations of both John and his brother Bobby.”

The article appeared unchallenged on the site for 132 days. Mr Seigenthaler learnt that his biographer was anonymous, and his search reached a dead end with the knowledge that he or she was a customer of BellSouth Internet, which refused to divulge more information, citing privacy laws. Instead Mr Seigenthaler, whose career has included breaking stories about corruption scandals and personally stopping a suicidal man from throwing himself off a bridge, wrote a furious article in USA Today , the national newspaper of which he was the founding editorial director.

In it he called Wikipedia a flawed and irresponsible research tool. He added: “At age 78, I thought I was beyond surprise or hurt at anything negative said about me. I was wrong.”

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