The founder of the Wikipedia online encyclopaedia criticised the Education Secretary yesterday for suggesting that the website could be a good educational tool for children.

Mr Johnson described the internet as “an incredible force for good in education” for teachers and pupils, singling out Wikipedia for praise.

“Wikipedia enables anybody to access information which was once the preserve only of those who could afford the subscription to Encyclopaedia Britannica and could spend the time necessary to navigate its maze of indexes and content pages,” he told the annual conference of the National Association of Schoolteachers and Union of Women Teachers (NASUWT) in Belfast.

But Larry Sanger, who helped to found Wikipedia in 2001, said that the site was “broken beyond repair” and no longer reliable.

Wikipedia is among the top ten most visited sites on the internet, containing more than six million articles contributed only by members of the public. But it has been criticised for being riddled with inaccuracies and nonsense.

Last month it was revealed that a prominent and long-standing Wikipedia contributor had lied about his identity, having claimed to be a tenured university professor, when he was in fact a 24-year-old college drop-out.

Concerned about the website’s integrity, Mr Sanger left Wikipedia, and two weeks ago launched an online encyclopaedia called Citizendium.org, which he said would be monitored and edited by academics and experts as well as accepting public contributions.

He told The Times: “I’m afraid that Mr Johnson does not realise the many problems afflicting Wikipedia, from serious management problems, to an often dysfunctional community, to frequently unreliable content, and to a whole series of scandals. While Wikipedia is still quite useful and an amazing phenomenon, I have come to the view that it is also broken beyond repair.”

Nick Gibb, the Tory schools spokesman, said: “A huge amount of the current curriculum, particularly in history, is devoted to teaching children to be discerning when it comes to information on the internet.

“It appears the Secretary of State is not quite as modern as he needs to be in this information age.”

Mr Johnson also used his speech to call on social networking websites to stop pupils posting inappropriate videos of and abusive comments about their teachers on the internet.

In one case a female teacher’s head was superimposed on to a pornographic photograph.

Mr Johnson said that the online harassment of teachers was causing some to consider leaving the profession. He called on the providers of websites to take firmer action to block or remove offensive school material, in the same way that they have cut pornographic content.

However, Chris Keates, the union’s general secretary, told Mr Johnson that his call was likely to have little impact.

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