In Bristol, after the success of Exploratory, an ambitious multimedia science centre is to be set up. Judy Redfearn talked to Martin Freeth
It's just 18 months since Martin Freeth was appointed head of the BBC's new Multimedia Centre. His previous science productions include The Burke Special, international co-productions such as The Mind Machine and The Trouble with Medicine, and numerous Horizon programmes. "I am delighted to have helped the BBC wake up to the possibilities of interactive media", he says.

So delighted, in fact, that he is leaving. He's going back to the place where he cut his multimedia teeth three years ago, on a series of televised debates hosted by the Exploratory, Bristol's hands-on science centre, the first in the country. Freeth will be director of Science World, part of Bristol's Landmark Millennium project to reinvigorate its historic harbour side.

Public science displays tend to get a mixed reaction from the public. Parents like them, children love or hate them, and scientists tend to call them either "contributions to public understanding of science", or "dangerous simplification".

Freeth is confident that the job "will allow me to combine 20 years' science programme-making for the BBC with much of the frontier interactive media I know about".

When it opens, at Easter 2000, Science World will succeed the Exploratory. Right now, it's just a disused car park. That will be swept away: Freeth plans to use broadcasting and interactive media to create "the first in the next generation" of hands-on science centres.

It is one component of Bristol 2000, which was awarded pounds 41m of lottery money last year. The others are Wildscreen World - a visitor attraction about ecology and biodiversity - and a series of new public squares and open spaces. An Arts Council funded Centre for the Performing Arts is to be built on a adjacent site.

The three new attractions will provide "a focus on the media, science, nature and art that is unique", says Gillian Thomas, chief executive of Bristol 2000 and former deputy director of London's Science Museum. Wildscreen World, which will feature an electronic zoo, is also headed by a broadcaster with an interest in interactive media: Chris Parsons, former head of the BBC's Natural History Unit. The two "Worlds" will be closely linked.

Three years ago, the Exploratory debates provided a move towards multimedia for Freeth. They featured between eight and 11 scientists, who discussed issues such as women in science, who controls science, and science and behaviour. The debaters supported their arguments with video-clips chosen from hundreds from the BBC's archive, accessed via laptop computers.

The debates heralded a move for Freeth away from science programming into multimedia. The BBC was already thinking seriously about digital television and its interactive possibilities. Freeth became involved in devising a multimedia strategy for network TV, and bid successfully for money set aside by the BBC director-general John Birt, to establish the BBC Multimedia Centre.

It is responsible for the BBC's 8,000-odd Web pages, training BBC staff in new media, and developing new interactive media. These consist of Internet on-line services, broad-band interactive media and other media such as CD-Rom and DVD (Digital Versatile Disc), the successor to CD-Rom. Freeth plans to use all of them, including broadcast TV.

A couple of the Multimedia Centre projects give a flavour of what to expect. The Web, a TV programme for children about animals, has an accompanying Internet site that allows users to ask questions of "masterbird" and talk to each other, becoming virtual characters if they wish. The Bach Project comprises a TV programme and interactive CD-Rom that lets the user dissect Bach's music in a way that would be impossible with any other medium - even live players and singers. Individual parts can be picked out, given greater prominence or played by different instruments.

However, interactive media demand a multifaceted approach to story-telling that is quite unlike the linear approach of ordinary programme-making, and many over-stretched BBC producers were not interested in Freeth's concepts. But interactivity will be at the heart of Science World. "The educational power of making choices is very great," he says.

On entering, visitors will be able to choose an experience appropriate to their age, interests and knowledge by picking up a smart card which records their characteristics, such as age and sex. Plugging it into the various exhibits will ensure that the response is aimed at the right level.

Traditional hands-on exhibits will be enhanced by computers, letting visitors explore physical principles more fully. But the true value of the new media is their scope for illuminating concepts that are difficult, or impossible, to convey with a physical hands-on exhibit.

For example, consider Einstein's theory of special relativity. "You can't do a hands-on exhibit on relativity", Freeth says. "But you can put the exhibit into a virtual world, allowing you to experiment with the speed of light and see what happens".

Biology, too, will benefit from the new approach. Visitors will be informed that "you are amazing" and shown how they got that way, through interactive exhibits on the brain, the senses, sex and genetics. Armed with a picture of themselves, they will be sent in different directions, via a series of "story lines", to the rest of Science World (or its neighbouring attractions) to find out about the products of the human mind, be it science or art. The new media will also bring cutting-edge research, its uncertainties and processes to Science World's visitors. A "newsroom" will interpret the latest science stories and let people air their views of developments.

Debates on controversial science topics will be televised from an on- site studio. Freeth is also planning for groups of teenagers to make their own TV programmes on a topic linked to their experiences at Science World.

But Science World can involve people from further afield than Bristol. By collaborating with other science centres via the Internet, geographically distant individuals or groups will be able to participate in experiments. Freeth envisages teenagers in Bristol working with a group in Boston to take measurements of characteristics of the Sun which cannot be carried out in one place.

His hope is that extending the scope of a hands-on science centre will allow it to reach a wider cross-section of the community - especially adults and pre-school children. Most visitors to traditional hands-on science centres, such as the Exploratory (which has 200,000 visitors a year), are schoolchildren, their families and teachers. Over the next two years, the Exploratory will be the testbed for many of these new ideas.

The vision extends to the end of the tour, where visitors will receive a print-out of what they did and achieved during their visit. Of course, not everyone will want to be so organised, admits Freeth. For those for whom all the interactivity is just too much, he is planning a silence space. "It will be sealed in - full of comfy cushions and beautiful scientific objects where you can escape." But he's not planning to go there himself for some time yet. His work is only just beginningn