Why comedian plus punchline equals guffaw

Now, however, the Science Museum is to embark on the first scientific examination of what makes Londoners laugh.

Audience members at a comedy night to be held at the museum's Dana Centre on Thursday next week will be able to rank jokes on an electronic keypad.

Organisers hope to rate them in terms of funniness and taste and also establish how soon after a person's death it is acceptable to make fun of them.

Possible test jokes might be John Cooper Clarke's claim that Elton John planned to record a memorial song for Mother Teresa called Sandals In The Bin, or Ricky Gervais's assertion that Nelson Mandela proves that prison works because "he hasn't reoffended".

Jonathan Ross's quip that Abi Titmuss has been "tied to more bedposts than David Blunkett's dog" could be assessed for both sexism and political relevance.

Catherine Tate's recent sketch about an Irish family giving each other "novelty terrorist gifts" might be up for debate, as might the question of whether endlessly repeating the phrase "Am I bovvered?" is funny.

Comedian Christopher Green will host the evening in the guise of a statistician asked by Gordon Brown to discover what people "on the street" find amusing. The idea that our dour Prime Minister would be interested in humour might sound like a joke but Green is serious about his comic mission.

"This is the first time we have tried to quantify jokes and we really don't quite know what people's reaction will be," he said. "It is a tongue-in-cheek experiment but we hope to get some interesting results from it. I think the fact we are doing this first in London will be interesting. It might be that people are a lot more liberal in the capital. But a lot of this material is usually done in comedy clubs, so a more serious audience might react differently."

Following the evening, experts from the museum will analyse the results. Mr Green hopes to repeat the experiment around the country.

"The Science Museum event is just a trial for this," he said. "We hope to expand it and involve more scientists. I think the science of comedy is something that hasn't really been explored."

WORLD'S FUNNIEST JOKE?

Psychologist Dr Richard Wiseman of the University of Hertfordshire recently studied 40,000 jokes and almost two million ratings to find the funniest. This is his winner:

Two hunters are out in the woods when one of them collapses. He doesn't seem to be breathing and his eyes are glazed. The other man whips out his phone and calls the emergency services.

He gasps: "My friend is dead! What can I do?" The operator says: "Calm down. I can help. First, let's make sure he's dead."

There is a silence, then a shot is heard. Back on the phone, the man says: "Okay, now what?"