Wikipedia - how accurate is the online encyclopedia?
It is one of the 12 most visited websites in the world, indispensable to millions of users. From Aa ('an 80km river in northern France') to ZZ Top ('an American blues rock band'),online encyclopedia Wikipedia has entries on just about everything.
But last week the website was engulfed in controversy after it was revealed that one of its main contributors had faked his qualifications.
Writing under the pseudonym Essjay, Ryan Jordan, who had edited more than 20,000 pages of information, claimed to be a professor of theology.
But when a magazine published an article on Wikipedia two weeks ago, many were puzzled to see 'Essjay' also had a specialist knowledge of American pop singer Justin Timberlake. It transpired that Jordan was actually a 24-year-old college dropout from Kentucky, and three days later he resigned from Wikipedia.
The scandal has thrown the authority of the encyclopedia into doubt. Critics argue that anyone with access to the internet is allowed to edit the entries, though Wikipedia insists that the sheer number of users ensures errors are swiftly corrected.
But not everyone is convinced. Here, four well-known personalities examine their own entries on the website and give their verdicts...
The internet is like a sprawling American city, mostly ugly, repetitive and tedious, hard to find your way around, unfeasibly vast.
But occasionally you glimpse little pockets of green or survivals from a previous age. When I chanced upon Wikipedia, it was a bit like that, a cooler, more peaceful place in a howling desert.
Unlike so many of the supposed resources on the net, it seemed to be trying to check and marshal its facts.
No, it's not perfect. It will never have the magisterial reliability of the 1911 Edition of the Encyclopaedia Britannica - which you can also find on the web, but which is of course almost a century out of date.
Wikipedia has other faults, too. I discovered, to my vain delight, that there was even an entry about me. I also discovered it was in many ways wrong, and in other ways motivated by a hostile Left-liberal bias.
I thought I should put this right and ran, rapidly, into a buzzing swarm of protest. Other contributors insisted it was unethical for me to do this.
Neutrality might be impossible. But transparency about who wrote what is completely possible, so I ensured it was obvious I had made the changes myself. In the end, other contributors intervened, generally in a civilised way, and the result was a lot more accurate than before.
I'd be very careful to intervene anywhere else. Some controversial sites are white-hot with anger. Indeed, some matters are so controversial that reference books and history books have to stand back until the matter is settled.
But in the end, I'm in favour of Wikipedia. It seems to me that most users and contributors are trying to reach the truth in a reasonable manner. And that can never be a bad thing.
I had never read my Wikipedia article before. Now I have, I've lined up with critics who say the online encyclopedia is rubbish. 'My' piece is full of glaring inaccuracies and near-libellous stories, and it is hopeless if you really want to know about me or my life.
It says I went to the upmarket Belvedere School alongside Derek Hatton - a bit difficult, that, since it was an all-girls school and I actually attended a State grammar school, the Liverpool Institute High School for Girls. It's wrong on other basics, such as the date I married my second husband, John Jones.
There is not one word about what I did at the Department of Health under Margaret Thatcher. I blew steam, however, at the complete misrepresentation of the events surrounding the salmonella scare of 1988, which led to my resignation.
Wikipedia makes me sound completely barmy.
Since 500 people a week were becoming sick and some 60 died through eating eggs, I'm proud I raised the issue. Subsequent tragedies such as BSE suggest I was spot-on.
Then I fell off my chair laughing.
My appearance on TV's Hell's Kitchen was apparently 'somewhat overshadowed by rumours that she was having a transatlantic affair with actress Charlie Jubb'.
Who? Never heard of her, never met her, as far as I know. I don't even think she exists.
So don't take this 'encyclopedia' seriously. It's less accurate than most gossip columns.
If you need any information about me, go to edwina.currie.co.uk - what's there is the truth, as I wrote it myself.
I recently stood successfully for election as Rector of the University of Dundee. Canvassing a female student, I told her I had twice been president of the Students' Union there.
'I know,' she replied. 'The university were so anxious to get rid of you they amended the Charter so nobody could stand three times.' Stunned, I asked her how she knew that obscure 23-year-old fact about my life.
'Oh, I looked you up on Wikipedia.'
Wikipedia - the teenagers' first resort for knowledge. Over the past two years I have looked at my entry from time to time. I have, of course, been deeply involved in controversy over the CIA's extraordinary rendition programme and the use by the United States and the UK of intelligence obtained under torture - I was sacked as British Ambassador to Uzbekistan after revelations about the country's brutal regime.
That has caused warring groups of pro and anti-Bush bloggers to continually amend and reamend my entry. Had I 'stated' or 'claimed' something? Arguments rage over the nuance.
But the result is fair and authoritative - I am proud of my entry.
I use Wikipedia a lot, but with caution. It is open to malicious manipulation.
My political opponents have made concerted attempts to discredit me by inserting false allegations of racism and Islamophobia. On a more mundane level, my entry has lots of small, irritating errors. Until I got them corrected, my date and place of birth were wrong.
The current entry is too gayist. It says I 'recently' extended my concerns beyond gay rights. Not true. Since the age of 15 I have been involved in a broad human-rights agenda - from the death penalty to animal welfare, women's equality and green issues.
The omissions are odd. I have written six books (most of which are not cited) and more than 3,000 published articles (a sizeable sample of which are on my website - www.petertatchell.net).
Little of the information in these sources has made it into Wikipedia. Despite these criticisms, the idea of a democratic, participatory, grass-roots-generated online encyclopedia is laudable.
My advice? Use Wikipedia as a resource, but check controversial claims with other sources. As my entry shows, Wikipedia is open to abuse.