The Gold Loebner medal has never been awarded
The Science Museum, in London, UK, is hosting the Loebner Prize, which hands medals and cash prizes to the inventors of computer programs that can maintain the most life-like dialogue.
The competition is a variant of a stricter test first thought up by pioneering mathematician Alan Turing.
He suggested that computers could be said to be intelligent if their responses to conversational cues were indistinguishable from those of humans.
Unclaimed prize
The competition is taking place on 13 October, at the museum's Wellcome Wing. This year, eight entrants have made it through to the final; one of the finalists is the winner of the 2000 contest.
The Gold Medal, and a cash prize of $100,000 (£69,000), is awarded to the program that convinces half the judges it is human by spoken responses.
The Silver Medal, plus a cash prize of $25,000 (£17,000), goes to the text-based program that convinces half the judges.
No Gold or Silver medals have ever been awarded. Also, every year, a bronze medal, and $2,000 (£1,400) cash, goes to the most convincing entry.
Friendly sites
In the early years of the competition the judges were restricted in the questions they could ask, the topics they could choose to talk about and were unable to be sarcastic in their responses.
In a move that shows how the competition is developing, some of these restrictions have now been relaxed and the chatty programs can be asked almost anything.
Last year, a program called Alice, developed by Dr Richard Wallace, took the bronze prize. Dr Wallace has now established the Alice Foundation, which is driving the development of the chat software so it can be used more widely.
Visitors to the Alice webpage can get a chance to converse with the software. Some webpages are adopting chatbot software to make their sites more interactive and friendly.
Other entrants this year include Peter Neuendorffer, a folk piano player and a self-taught programmer, and Australian computer scientist Chris Johnson, who has entered the competition twice before.