Ham-acting that makes you squirm, faux olde worlde country accents and tatty frilly frocks more suited to a tearoom - often an audience shuffles out from museum theatre more embarrassed than starstruck.

But the frilly frocks have (almost) all been folded neatly back into their olde worlde wooden trunks and the cloying accents have dampened down. Museum theatre has come out of the wings and on to centre stage.

In a 2006 survey by the International Museum Theatre Alliance (IMTAL), half the respondents said their visitors came specifically to see museum theatre.

But what is it they come to see? Not even the star players in museum theatre can provide a definition.

It could be a guide besuited as a Victorian bank manager speaking about their character (third-person interpretation); an actor dressed as a 16th-century pirate and dotting their conversation with "Ahoy, me hearties", (first-person interpretation); someone narrating a tale, just as a storyteller would; two people having a conversation, part scripted, part ad-lib; or just straightforward acting - reciting scripts and playing parts.

Standing up in front of an audience and saying your lines might count as traditional museum theatre. Milestones, a county council museum in Basingstoke, Hampshire, has used this simple form to draw in those who aren't attracted by the museum's recreated historic street scenes, which resemble a Hampshire village from the Victorian era to the second world war.

Milestones' play about Gypsies, set in the late 19th century, was "inspired by the fact that no Gypsy came to visit our museum", says Jane Glennie, the team leader of costumed interpretation. "You have museum theatre because you can't always persuade people to come to your museum otherwise."

Enticing people over the threshold is often seen as the first job of museum theatre. "Having a costumed interpreter guide gives people permission to come in," says Ruth Turkington, the visitor services manager at Ulster Folk and Transport Museum, a 170-acre outdoor museum of buildings recreating early 20th-century Ulster life that uses costumed third-person interpretation throughout.

Go into the Corner Shop, and you'll be met by a white-haired woman wearing an ankle-length apron and a gentle smile, standing before rows of shelves containing jars of old-fashioned humbugs and boiled sweets, which she'll measure out, in small portions, for sale.

Places for debate

"It makes it like a domestic setting - it's like you're being invited into the space," says Turkington. "The audience then feels that it's all right to ask questions."

One of the aims of museum theatre, in all its different forms, is to provide a spur for conversation. "A lot of museums are now redefining their roles," says Turkington. "They are there to preserve and curate, but they're also there to negotiate meanings with the range of communities around them. Museums are places for debate."

Tony Jackson, a senior lecturer in drama and co-director of the Centre for Applied Theatre Research at the University of Manchester, is conducting a three-year research project into the different ways in which performance is being used in museums and historic sites.

This will culminate in an international conference in Manchester in April 2008. As part of the project he worked with Manchester Museum on a performance.

"We wanted to get away from single character presentations; we wanted dialogue," he says. "It's about getting people into debates. We wanted at least two actors, confronting each other. The audience are then given sets of lenses through which they can see things."

Jane Glennie saw Milestones' Gypsy play as a tool for retelling Romany history and challenging ingrained prejudices. The characters expressed all shades of opinions and prejudices, from the perspective of Gypsies (played by non-Gypsies) to a pith-helmeted "Gypsiologist" who condemned Gypsies as dirty "Pikeys".

Glennie says: "We can play devil's advocate, and we did. Our aim is to create a dialogue."

But why do these dialogues have to take place in the past? "It's safe. Because we've set the play in 1900, people can say 'That's 100 years ago, it doesn't affect us today,' but it does," says Glennie.

This comforting safety means more than 70 per cent of museum theatre is historical, from performances about the Napoleonic wars to pirate programmes and immersive theatre about Victorian murderesses.

Turkington is also keen to use museum theatre to tackle tricky issues: "Performance in an exhibition about the Troubles puts a safety net between the audience and the exhibition. You're not looking straight at the material itself."

But not all museum theatre is good museum theatre. Robert Forshaw, the living history coordinator for Armagh City and District Council and IMTAL-Europe's chairman, says:

"Your interpretation is only as good as the person who's doing it. Actors are expensive. We look for people who have a history qualification and are interested in the subject. Unfortunately, there's no qualification in historical interpretation. We need accredited training so we can maintain standards."

Challenges of performance

The challenge for the live interpreter is to quickly let the visitor know the difference between third- and first-person interpretation, says Jackson, from the Centre for Applied Theatre Research.

"Sometimes it's difficult to know what the game is," he says. This means rather than draw the visitor in, they can be repelled, unwilling to take part when they don't know what's expected of them. "If you don't set it up the right way there can be confusion and misunderstandings. You need to think carefully about how the audience can be inducted."

Anna Farthing, IMTAL-Europe's director, believes a museum theatre production doesn't just have to be good, but very good, meeting far higher standards than mainstream theatre, and really engaging the audience: "If you're not holding them, they don't have to stay. They can just walk out. They couldn't really do that in a conventional theatre."

The performance itself has to be designed with a very discerning ambulatory audience in mind. "You've got to give them the right to opt out at any particular point," says Jackson. "You've got to make the performance allow for this. They may also join halfway through. The performance must allow that to happen, and not be badly affected by it."

Jackson believes the museum is just a stage about which visitors strut about. "Museums are theatrical spaces. They often talk about
audiences rather than visitors. People often arrange themselves in a semi-circle around the exhibitions, rather like around a theatre stage. In a way, it doesn't take much more to place live performance there."

The one thing it does take is commitment and understanding by the museum itself. Not every museum welcomes luvvies wandering among their display cabinets. "Old-school museum professionals are suspicious of theatrical types," says Turkington.

Jackson's answer is to try to get all museum staff involved from the outset. "At Manchester Museum we did a dry run for museum staff and took their comments on board," he says. "Everyone was given a feeling of ownership. It wasn't just actors coming up from London and getting in the way."

There are also practical considerations and conflicts. Jackson gives examples of museums that have drowned the actors out by refusing to turn off the oral commentary on displays during performances.

But Turkington is convinced of the power of museum theatre to improve the museum experience. "People's recollections of their museum visit are much stronger if they've been observing museum theatre," she says. "It's animating the objects using the human voice. Drama can unleash the power that objects have."

Dea Birkett is the director of Kids in Museums

www.imtal.org/MOsurveyreport.pdf