Twenty five per cent of those who have visited Wikipedia have read something they know to be inaccurate, according to Rasmussen Reports.

The occurrence of mistakes in Wikipedia is no surprise; there are errors in every reference text. A study conducted by the British journal Nature concluded that on basic scientific fact, the number of errors found on the site is comparable with the Encyclopaedia Britannica, but Wikipedia does not just include scientific fact.

Comscore data shows that usage of the site has increased by nearly 12 per cent in the past year, attracting 15.5 million unique UK users in October alone, about 40 per cent of all adult users.

This number of users on an “open-edit” platform, combined with the broad coverage of topics that Wikipedia offers, has attracted a unique set of errors driven by misinformation, self-interest and malice.

The mistakes on Wikipedia fall into four categories: vandalism, battlegrounds, proving a point and accidents.

“Wiki-vandalism” is the purest form of abuse on the site and the easiest to detect. It is essentially cyber-graffiti, and the process is simple: a user logs on to a page and writes something he or she knows to be wrong.

David Beckham’s page once described him as an 18th-century goalkeeper, Tony Blair was accused of having pictures of Hitler on his wall as a teenager and Michael Winner’s 2007 death, like that of so many other celebrities on Wikipedia, was greatly exaggerated.

Where a controversial character is concerned, a Wikipedia page can quickly descend into a battleground for supporters and detractors and in some cases has to be locked by editors.

Sir Norman Bettison, the Chief Constable of West Yorkshire, told his staff to monitor his page after he was described as “greedy, vain and moronic”, Police Review magazine reported. Sir Norman’s page became the centre of a debate on policing methods last year, his online reputation veering hourly from “controversial” to “pioneering”.

In extreme cases Wikipedia locks pages to prevent further editing, a necessity during much of George W. Bush’s eight years in the Oval Office, as his page received some 40,000 edits, mostly inaccurate and offensive.

It is increasingly common for pub arguments to conclude with the phrase, “Wikipedia it”. Once home the proponent checks the fact in question and then e-mails the link to his adversary, winning the argument — unless the fact is “wrong”, in which case it can be changed first.

Fanciful, you may think, but “Wikiproof” has even been used in Parliament.

When David Cameron and Gordon Brown clashed in February over the age of the artist Titian, a suspicious edit shortly afterwards changed the artist’s age at death from 90 to 86 to suit Mr Cameron’s argument. The change was logged to an IP address at Conservative Central Office.

The most common errors on Wikipedia, however, are genuine mistakes, added in good faith and motivated by misinformation rather than malice.

A study by Frozennorth.org added one small mistake a day to the website for five days and found that none of them had been removed several weeks later.

There is no way that every page can be fact-checked every minute of every day, and therefore as a serious research tool the website is flawed.

Although Wikipedia is underpinned by noble principles, its sheer size ensures that it will always remain a vast collection of knowledge, fact and fiction.

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