TECHNIQUE / Time to face up to the facts: There's more to it than mere words. Nick Curtis talks to three playwrights about what they do before they put pen to paper

It's the dirty work, the grind, the labouring of playwriting. Behind the beauty of imaginative invention lies the beast of research. Put a factual foot wrong in a play and someone will notice. Worse, they'll let you know they've noticed.

David Hare found the lengthy, painstaking process of interviews and investigation into the church, judiciary and the Labour Party that was necessary for his sweeping National Theatre trilogy essential as a means of staving off isolation. 'You see plays which are supposedly about man's universal condition,' he says, 'but in their themes of loneliness, neurosis, anxiety, they are often about nothing more than what it is like to be a writer, sitting alone with a typewriter.'

Not, he adds, that you should forget to be a writer: 'Once you've done the research you have to throw it out,' he continues. 'Nothing annoys me more than when the trilogy is described as 'documentary theatre'. However much I research, I insist on making as fundamental an act of imagination as if I'd produced it from within myself.'

If anything, David Pownall's research is even more involved than Hare's. For Pownall, it's a constant process from which a play may evolve - or not. He came upon the idea for Elgar's Rondo, currently at the Royal Shakespeare Company, during rehearsals for a previous play at Birmingham Rep. While researching the life of Neville Chamberlain for My Father's House, he discovered that Chamberlain had been in the audience for Edward Elgar's inaugural lecture as Professor of Music at Birmingham University, a post the composer took despite his loathing of academics. 'There were two kinds of betrayal in the room, one listening to the other. The coincidence intrigued me,' he says.

He began listening to Elgar's music and reading biographies, then visited as many places connected with the composer as he could. A prime source of inspiration was the derelict Worcester asylum where Elgar was conductor of the staff orchestra in 1880. 'I desperately tried to incorporate that into the play, the idea of Elgar conducting for the inmates, but it wouldn't work,' says Pownall. 'Still it increased my understanding of the man in 1911 performing to London audiences - to a different type of lunatic.' After writing the play, Pownall found he had enough material left over for a BBC radio script.

Hare, too, found himself with surplus but fascinating material and channelled a fraction of the overspill of unused interviews and observations into his 250-page book Asking Around, also a vivid account of the research process.

On the surface, this is a long way from the working method of John Godber who - received wisdom has it - never writes about anything outside his own backyard. Five years studying the life of playwright John MacKendrick for his MA was, he says, 'enough research for anyone'. Still, this didn't prevent him learning judo and asking a world champion to sit in on rehearsals for Blood, Sweat and Tears, his play about self-defence for women. Or, for that matter, for reading books and watching videos about mining for Salt of the Earth, a mammoth history play on the subject (rumoured to be for the National). And, apparently, for his as-yet unwritten play about pornography, he's read almost all that's been printed . . .

All Godber's plays, he insists, are authentically researched, through observation of life. 'I'm not happy listening to people telling me about their lives and reproducing it because it seems like a kind of cheat,' he explains. So it is that the characters of Bouncers, his play about doormen and club-goers, were absorbed 'by osmosis, usually on the receiving end'. And his latest play, April in Paris - about an ex-builder and his wife on a disastrous, redundancy-funded holiday in Paris - was sparked by family redundancies, by his parents never leaving their coach on a trip to Paris because it was raining, by Godber himself never having been abroad until the age 30. 'These facts were backing up in my mind, and the result was the play.'

In research as in entertainment, though, you can't satisy all the people all the time. Hare, now relaxing with a new version of Brecht's Life of Galileo for the Almeida (where the scientific and biographical research has already been done), has recorded his exasperation about wilfully misguided Labour Party critics who protested that John Thaw, in The Absence of War, had neither red hair nor a wife called Glenys. 'There are things I've got wrong,' he admits. 'Apparently you can't be a knight and a QC, as happens in Murmuring Judges. But it's important to me that the atmosphere of the plays should be as authentic as possible.' Criticism of his accuracy, he says, is often bound up with the emotional response to a play: it was only journalists who for personal or political reasons disliked Pravda, his expose of the press and its barons, and criticised the play's journalistic authenticity.

Godber claims he has never been caught out, but 'I've caught others out: two very famous critics came to see April in Paris in Hull and said the backdrop painting was by Toulouse Lautrec, while criticising the characters for their ignorance. I wanted to say, you twats, it's Picnic at La Galleria by Renoir.' Pownall received a 'long and polite' letter from someone who hadn't seen Elgar's Rondo, pointing out that no one called Elgar 'George' and hoping that, if Pownall did have anyone calling him 'George' that this could be rectified before the play travelled to Newcastle.

For all three writers, research has its limitations. 'Scholarship can kill,' says Pownall. 'You have to be a pirate, not a professor.' Although he studies his subjects in great depth, he's aware that he can't 'do justice totally to any historical figure: you have to carve them up'. Godber, however, can't write without personal identification: 'I couldn't write a play about someone living in Russia, say. I couldn't project that. I would have to get in there.' Hare, similarly, could not write a play based on research that did not 'strike some deep chord within myself'. He prefers too, an objective distance rather than a total immersion in the subject. 'You shouldn't be a writer if you can't imagine what it's like to be somebody else. For me, John Berger wrote better work when he was an urban sophisticate than when he started pretending to be a peasant: he's a very unconvincing pig-farmer.'

'The Absence of War' is in rep at the National Theatre (071-928 2033)

'Life of Galileo' previews at the Almeida (071-359 4404) from Feb 11

'April in Paris' opens at the Ambassadors (071-836 6111) on Feb 1

'Elgar's Rondo' visits Newcastle Playhouse March 21-26 and transfers to London later this year

(Photograph omitted)