It seems a simple idea, inviting members of the public to help produce an exhibition or event at your museum. Everyone benefits from the process and new partnerships are formed, says the rubric.

But co-production is far from straightforward. It can raise uncomfortable questions about meaning and control and can be a traumatic and troubling process for all involved.

"The term is bandied about but it's a very problematic area," says Bernadette Lynch, a writer and museum consultant who is developing a book on democracy and dialogue in museums.

"Apart from the term itself not always being appropriate, we should also be asking whether the institution is willing, or able, to offer co-production and what it means for museums to share authority in this way."

What happens to the participants' contribution after the exhibition is key, says Lynch. "Will it be sidelined, or will it become part of the museum collection? This is crucial because documentation is the centre of the museum's power," she says.

Co-production means different things to different people and this is part of the problem. Lynch says that as well as the need to define their terms, museums must also be clear about the terms of engagement, and what non-museum professionals can hope to gain.

"True co-production is a challenge to institutional control and museums have to be clear about what's on offer from the start. If it's not authentic, then it's coercion and it will leave a bad taste in people's mouths."

So what does co-production mean and when is it ever authentic? It's a form of production that goes further than consultation, where focus groups give feedback, or collaboration, where input from outside individuals or groups is strong but the museum still retains editorial control.

"True co-production probably hasn't been attempted," says Nadine Andrews, a creative researcher and consultant whose company, Culture Probe, has evaluated many projects in the museum sector. "The big issue is the control of meaning and how prepared museums are - or individuals within museums - to give up control."

"A lot of museums haven't had the internal conversation as to what co-production means to them," she says. "There may be individuals who have that aspiration but lack strategic support from the organisation as a whole." While this may be the case, Andrews points out that museums are generally aware of this and trying to remedy the situation.

"They may only want co-production on a particular project," says Andrews, who evaluated the 2007 Revealing Histories, Remembering Slavery project, a partnership of eight museums in Greater Manchester.

Slavery and other emotive topics that may also have a political dimension provoke particular anxiety, she adds. "Museums may want co-production and to give people public ownership, but its very nature means that they have a lot of anxieties around how they end up being interpreted."

Public passions

Museums are attempting to work collaboratively, but people rush into things and don't think about the mechanisms beforehand, says Andrews.

"They need to prepare properly for the very first contact - it's a lengthy and difficult process, but worth it. Participants need to feel there's a point to it. And if you have made the budget, physical space and other constraints explicit at the start, you have the scaffolding to cope if it starts going in a different direction."

Manchester Museum took part in Revealing Histories, Remembering Slavery, but while the museum has aspired to co-production, director Nick Merriman says he would not make bold claims.

"Revealing Histories, Remembering Slavery was probably the closest we've got to authentic co-production, but to be honest we found it harder than we thought. We were surprised by how passionate people are," he admits. "It's difficult to get it right and to manage expectations."

Contribution doesn't automatically mean inclusion, says Merriman. "It can be disappointing for people to see their contribution downplayed."

A more radical form of co-production is where a museum or gallery gives over a space and relinquishes curatorial and editorial control.

But this is unlikely to involve core collections, points out Mark O'Neill, head of arts and museums, Culture and Sport Glasgow. It looks like inclusion, but is actually disempowering for participants, he believes, because the museum has a responsibility to its audiences and communities.

"The museum or gallery should be providing their expertise. It's about sharing rather than giving up authority. If an exhibition is going to look professional and polished, people should be treated with respect and given intellectual as well as physical access."

Large national institutions, where the pressure to protect the 'expert' view is strong, are perhaps less likely to relinquish control in this way. "The higher the status of the objects, the more sacrosanct they are," points out O'Neill. "But it's about getting more than one perspective. The public has experience, opinions, reactions, which makes them experts," says O'Neill.

"Think of the thousands of objects from different cultures in the British Museum or the Victoria and Albert Museum - always labelled from the curator's viewpoint, and very rarely from inside the culture they come from. But there can be religious, emotional or nostalgic meanings, and that's the real value of involving lay people. It's supplementing the curatorial meaning."

New knowledge

The Natural History Museum (NHM) discovered as much in 2007 when it staged a series of events, including plant and specimen handling sessions, to mark the bicentenary of the abolition of the slave trade. "Slavery and the Natural World took us to a new level of consultation where the panel's influence on us was the most we'd ever had," says Tracy-Ann Smith, head of new audiences at the NHM.

The museum had "robust" consultation with a diverse range of groups, including an African grassroots organisation and a local tenants' association. It was not an easy ride, admits Smith.

"It was fraught at the start because of the challenging subject matter. There was anger and distress and we were shouted down on occasion, but as the trust grew, the sessions became easier and we started to think of one another as partners. We redrew the plans and they could see they were influencing us."

The museum's methodology was also critiqued by a different focus group of professionals. "We had three initial sessions where we took the role of note-takers only," explains Smith.

"The focus group thought that we should have engaged in dialogue from the outset, but at the time I strongly felt that we needed to listen first. They came up with ideas that I'd have said weren't within our remit, but when we looked at our collections we found material we'd never have thought to use."

There were a number of important outcomes, including research shared on the museum's website and educational resources, says Smith.

"We have new information that's beginning to inform our exhibitions, the way we represent ourselves and the history of our collections, such as the context of empire as well as exploration. It may be an uncomfortable part of our history that we had not thought about acknowledging.

"Our focus is as a science organisation, and we think about ourselves in a very scientific way, but looking at our museum in the context of our history and of slavery broadened our horizons.

"Staff also gained confidence to handle controversial issues," she says. "The process and our learning was as significant for us."

Like a reverse Antiques Roadshow, Smith found that people brought new cultural knowledge about the plants and specimens and the contributions of enslaved people to the museum.

"Some colleagues questioned why we were working in this way, but I personally felt very influenced and I'm proud that I went out of my comfort zone. It challenged us and helped us address the inherent bias of the European perspective of our older library collections."
Museums don't always realise how much they need to change, says Andrews.

"Fundamental shifts are needed and some of this has to be at the level of people's attitudes and assumptions. It's about reflexivity and seeing your own processes. It becomes a useful microcosm for talking about wider issues, and it's fascinating because it's all played out in the relationships."

Deborah Mulhearn is a freelance journalist
Ideas take space at Tate Liverpool

There is no fifth floor at Tate Liverpool, but a new project that brings together Tate staff, local community groups and internationally recognised artists imagines what would be exhibited there if one existed.

Fifth Floor: Ideas taking Space is an imaginative concept designed to push collaborative ideas further than the organisation has ever taken them. "It's partly a reaction to the Capital of Culture events in the city that many people felt excluded from," explains Peter Gorschlüter, head of exhibitions at Tate Liverpool.

A record of ideas and proposals was formed from a series of workshops asking people what they wanted to see in the exhibition. Gorschlüter says: "We wanted to feature the people of Liverpool and we were surprised by how radical some of the ideas were. One woman even suggested replacing the art with people."

Using Tate staff's knowledge of the global art world, the ideas were then matched with artists who were invited to respond. It went further than collaboration, says Gorschlüter, because some of the artists were willing to change the way they worked to include the participants.

Romanian artist Dan Perjovschi, for example, creates installations of cartoon-like figures that comment on cultural and current affairs. "He said that to simply respond to participants' ideas wasn't enough. He wanted access for them to his own installations.

"It's this opening up that makes the project so unique, so that the focus stays on people's ideas and imaginations rather than the end result," says Gorschlüter. "It's about imagination and inspiration. It's interesting that people - and not just journalists - immediately start asking about the quality, the success and the legacy of the project.

"It's a work in progress so we can't say what the quality will be, but such a question would never be asked about a professional artist's work. It's also unusual for an organisation like Tate because it's changed the way we work inter-departmentally. It shows that it can be done."

The exhibition opens in December and runs until February 2009.