Say hello to Jabberwacky, our best 'human' computer

A computer program will attempt to pull off the ultimate con trick tomorrow: fooling an adult into believing it is human - and in doing so claim the greatest prize in artificial intelligence.

A computer program will attempt to pull off the ultimate con trick tomorrow: fooling an adult into believing it is human - and in doing so claim the greatest prize in artificial intelligence.

The program in question - called Jabberwacky - started life in 1982 on a Sinclair home computer. Written by Rollo Carpenter, a British computer consultant, it is one of four that have been picked by the millionaire Hugh Loebner to take part in the annual Loebner Prize contest, where computer programs try to pass the "Turing Test". That challenge, originally set by the British mathematician Alan Turing in 1950, is straightforward. In a text conversation with no fixed topic a human should be unable to tell whether they are communicating with another person or a computer. If successful, the machine would have passed at least one of the requirements to be described as "thinking" - though Turing himself said it would be better described as "imitation".

Dr Loebner's grand prize of $100,000 (£55,000) for the first computer whose responses are indistinguishable from a human's is yet to be won. An annual $2,000 prize is also awarded for the computer program that is most human.

But even if Jabberwacky does not win, Mr Carpenter, who funds his project through his work as a business computing consultant, believes that it heralds a new era of interactivity. The computer Hal in the film 2001: A Space Odyssey, which appeared human by having a human voice and inflection could become a reality.

"I suspect in the future there will be ever-increasing move away from things like TV to things like the internet and other communications devices. Imagine where you have an iPod or mobile phone or little robot that sits on your shoulder which keeps you company as you walk along the street, or advises you on what to do. My approach is about making something that gives you companionship."

He has been running the Jabberwacky program at its website for some years, where it will engage human visitors in conversation. So far it has sorted through more than 3.3 million responses in 200,000 conversations to try to build a database of sensible responses.

"Right now [the program] is still pretty strange," admits Mr Carpenter. "It says unexpected things, which if you're of a certain mind is amusing, and makes people stay on the site. But that won't necessarily impress somebody who's coming to test it."

The Loebner Prize is run under strict conditions, where the competing programs must be run on a computer that is not connected to the internet, and run on their own on a computer in a room shared with a human being.

In an adjacent room, a human "interrogator" will quiz the four computer programs and one human - without any clues to their identity - and decide which are the machines and which the person.

That meant that Mr Carpenter had to add an extra layer to his program: simulated typing, including mistakes.