As director of Norwich’s Inspire centre, and a consultant to many others, Ian Simmons has seen most approaches. Most school parties leave children to explore as teachers do themselves. Some make children fill up worksheets, a few fill up with tea. One teacher even marched the class round, delivering a lecture at each exhibit while pupils sheepishly filled in their sheets. Amazingly, in a classic piece of un-professionalism you’d want to see on film, his teaching style was challenged by an onlooker. Unsurprisingly, he was not pleased!

Ian Simmons feels that getting the best out of a hands-on centre is no laissez-faire affair. In a place where pupils can discover and get enthused about science, what is called for is a stimulus sheet rather than a worksheet. You see why when you see pupils just filling in answers, without exploring the exhibits. So questions like “What can you find out about the Bernoulli blower?” work better than “Where is the Bernoulli effect useful?” Essentially, he recommends giving pupils very general things to look out for - questions they might discuss over lunch, on the train or in class, and well before they come to any conclusion or formal write-up. He adds that instead of channelling children’s thoughts, they become more adventurous through finding out than by being told what to look out for. But if on your visit you ever catch a lecture being given, please have the tact to break this idea gently.

Bristol’s Exploratory is England’s largest science centre. It’s a place where children get their hands on to science and get their curiosity stimulated. It’s also dark, but spotlights pick out things for children to interact with. They need no telling, and when let loose they shuffle through the shadows and get busy. The dark, they tell me, is a quietening device.

The children move lenses to focus an image or draw their outline on a mirror and step back to see if “they” change in size. They will queue six-deep to ride a cycle like fury, and thus power a television. They blow bubbles using all sorts of wire shapes, round, square or just odd - and wonder why they don’t get square bubbles. They make a colourful soap film the size of a window. Blowing yet more bubbles into a tank, they see them fall and then sit, mid-air, on an invisible layer of carbon dioxide.

You can spot big grins - and puzzled faces too. A 10-year-old does not know what to make of dipping wires into solutions and burning them in a flame. Another, no bigger than an umbrella stand, can’t quite make the right angle on an impressive hologram of a tiger. But they keep on moving, almost drug-crazed, seeking the next kick.

“Been here before?” I ask someone with a carrier bag and three jackets on his arm - a teacher. “Yes, we take a group every year. I love it. I still don’t know if they learn. But they love it too.”

The Exploratory, like similar galleries, follows the lead of “hands-on” guru Frank Oppenheimer, who created the world’s first hands-on science gallery, the San Francisco Exploratorium, in 1968. Today the Exploratorium has grown to 650 exhibits - wonderful, but surely enough to numb anyone’s curiosity.

Bristol’s 150 pieces are more than enough. Not only are they a treat but it’s nice to find exhibits not in showcases. For example there’s bubble blowing, bones to pick up and examine, inks to separate on blotting paper, spinners to colour-in and spin. I saw no abuse and little mess. The T-shirted gallery attendants, called Pilots, could spend their time helping instead of yelping.

Upstairs at the Exploratory you enter the light once more. At the time of my visit, it was full of hyperactive children - just a hint that the light-dark theory works. Here is the Stradivarium, a gallery said to be uniquely dedicated to music and sound. The world’s largest acoustic guitar is certainly unique, complete with its framed Guinness book certificate. A few children are inside the instrument, twanging the strings, getting a feel for a sound box.

There’s a large keyboard where they can walk-out a tune, tubes where they hear sounds from long and short pipes and little cubicles where they can test if their pal can identify the things they bash. Here too are all kinds of bridges to examine: arch bridge, beam bridge and cantilever bridge. Visitors can walk over a suspension bridge and feel what gives. And on an elliptical snooker table I could hit the other ball, no matter in which direction I took a shot.

If you wanted to cover sound, senses, forces, bridges, light or space you might come here. You might use the centre’s Pathways, teacher’s packs which help structure your visit as well as provide ideas for before and after activities. The Exploratory is also home to the Stardome planetarium - an inflatable dome with a projector. This isn’t unique but it is a turn-on to stars and stuff that I couldn’t recommend more highly. And as if this wasn’t enough, there are still more sideshows to round off your visit. For example, Puzzle Mania is newly installed, with 30 perfectly puzzling pieces from around the world. You can sort out the rats in a drainpipe, escape from the Colour Maze and at least try to come to terms with the Impossible Puzzle. Puzzle Mania runs until November 4. Bring the kids and your therapist.

Snibston Discovery Park is an unusual mix of science, industry, history and even snatches of art. Set in unassuming Coalville, near Leicester, it’s a true discovery to find a museum, golf centre, arboretum, fishing lake and nature trail with marsh and meadow - all squeezed into the 100-acre plot. It makes this Pounds 6m project the largest purpose-built science museum in England since the Second World War.

You can start in the exhibition hall, which looks not unlike an out-of-town superstore. First up is Science Alive, the hands-on gallery. At a glance you’ll see areas to explore the body, weather, and the environment. You can step right into a whirling tornado and see how it forms, take readings from a weather station or see the latest pictures from Meteosat, a weather satellite. You can see why the sky appears red or blue as beams of light scatter through tubes of liquid, and you can spin a solar system model to explain the seasons. And in the “windy city” you’ll see how the wind rushes past buildings which you have arranged as you choose.

There’s a good spread of secondary-school ideas here, but younger pupils could try their hand at generating power using waves, a waterfall and windmills. Or they could assemble the organs of the body, handle a skull or two and ride a bike beside a skeleton which copies their movements. Then there’s a simple and elegant computer survey to do and instantly see that 5 per cent of visitors have grey hair or none at all. Adults, including the 5 per cent, might want to slip into a soft chair and have a go (and fail) at puzzles like the Soma cube, in comfort.

Outside is Science Play, Britain’s first science playground and an idea to commend: here children discover why white clothes help keep them cool in the sun as they crawl through two metal tunnels, one painted white and one black. They might listen to the pan pipes, an array of pipes of different length, and hear different pitches of sound. They might whisper into a parabolic “satellite” dish and chat secretly with a pal at a dish some 30 metres away. And there are three see-saws - deceptively ordinary but one is pivoted in the middle while the others pivot on one side. This, I hear, generates nearly all the entries in the accident book and could be up for removal. You can don a space-like virtual reality headset and seemingly drive dodgem cars, or move about a kitchen and open drawers, or answer the phone. Just mildly impressive for Pounds 1 more. It’s meant to help develop spatial awareness but seems to develop headaches instead. There’s lots more: holographs, a solar house, 3D glasses to watch a slide show, a light gallery and the large-scale exhibits on engineering, extractive industries and transport completed with an ice-cream van.

Some while-you’re-here extras include the excellent guided surface tour of Snibston Colliery. This is well worth the extra Pounds 1. There is a sculpture trail with a giant toast-rack filled with slices of coal. Called “Daily Bread”, this is art, I think. There is a wheelwright’s workshop which was transported brick by brick from Sheepy Magna 15 miles away - it’s a sort of shrine to a range of nearly-lost skills. There’s also a willing and active education department and an events programme to tap into. Oh, and a smart cafe too. Snibston also houses the national collection of underwear, politely called contourwear, but Oh! shame, there’s nothing racy on show: a Twenties stocking, a Fifties corset and swimming cossies. They tell me the previous exhibition attracted the wrong sort of interaction.

“Feel free to touch all the exhibits” says the sign at Xperiment! a gallery in Manchester’s Museum of Science and Industry. Xperiment! is the hands-on, interactive gallery where fiddling with things is the main business of your visit. And if you ever confused museums with mausoleums, think again.

You walk towards a large camera as you enter: a small mystery until you go inside this human sized camera obscura and see the outside image - upside down, of course. This is a taster of Light, but Sound and Energy are covered too. You’ll find many things that touch the curriculum - like a large prism which splits up light into rainbow colours. Or a “snooker” game where you aim a beam, twisting mirrors at angles, to hit a distant “pocket”. Or a cloudy water tank where you place diverging or converging lenses in a light beam and see light rays bend in 3D.

Elsewhere you’ll just tickle the curriculum - but who cares: a flash gun fires on a sensitive screen and you can walk away as your shadow spookily stays put. You’re beckoned to push your hand into a concave mirror and its reflection pops out as if to grab you. Other gentle tricks continue the theme using polarised lenses, curvy sea-side mirrors, fibre optics and things that glow in ultra-violet light.

At the peak of the museum season, in the late summer term, children were arriving by the skip. Some were primed with worksheets with teacher’s orders to dot every “i”. Others had a more open brief: “Go and play, write about what you like.”

A queue formed around Racing Circuits, the classic electricity game where children move a metal loop along a contorted wire and hear a buzzer if they touch it. Others paused, just long enough to see them thinking, before making an electric circuit which needed just two people to make it work. And others were attracted to, and puzzled by, the “human battery” where they could test pairs of metals, brass, copper or steel and see which generated the most juice. But no one queued around a gold-leaf electroscope; did they ever?

Like many interactive galleries, there is no measuring how much Xperiment! infiltrates how many brain cells per class.

What does infiltrate is a “Welcome to science!” message: science is attractive, fun, and not filled with failure. Gallery manager Bhagwant Singh will tell you their job is just part of the business of “sciencing”.

“It’s only the beginning of the science process we’re dealing with. We’re not asking them to draw conclusions, or demanding answers all the time, we’re just inviting them to observe, to feel and see for themselves. We want to put across a positive image of what science is about.”

Elsewhere you’ll find enough to fill the day: until October 6 there’s a display of amazing K’nex models, as well as the chance to snap together your own masterpiece. Or see the steam-driven mill engines and trains in the airy Power Hall. Sniff your way round the Victorian sewer. Stare at the acromegalic characters in a railway station diorama. Then there are cameras, aeroplanes, and scientific instruments as the museum genre dictates. Nearby are other attractions, such as Granada television studios. To do your feet a favour save that for another time.

Within sight of the Cardiff Bay barrage, one of the biggest civil engineering projects since the channel tunnel, is Techniquest, the UK’s biggest hands-on science discovery centre. It’s bright, gleaming and brand new. It took Pounds 7m to take Techniquest out of its original home in a gas-board showroom and into the really big league.

In one turn of the head you can take in that it’s going to be fun. You could launch the children in and snack on an ice in the cafe, but even the most science-phobic, compulsive eater will want to launch themselves into this must-see, must-do gallery. There is quite an assortment of devices to interact with and there is no overt theming - so you take it as it comes.

You might drop a magnet through tubes made of plastic, copper and steel and wonder why they fall at different speeds. Or pick up a teapot and try to pour a cuppa - there’s a spinning gyroscope inside to thwart you. Or play director and make an animated video: you move Play-mobil models in front of a camera, snap a frame at each move and then play the film back.

Why not put yourself in a movie as they do with the television news backgrounds? Or watch a TV screen and press a button to zoom in to see “atoms” or zoom out to see the earth, the solar system and the galaxy?

You can blow a giant smoke-ring, make a battery with “orange juice” or sink a boat with air bubbles in a model of the Bermuda Triangle. You can hear sounds change in the Doppler effect, as a sound spins over your head. And you can push air through models of the different shapes your throat makes and actually hear how shape affects the sound. You’ll certainly pause at a Heath Robinson-ish machine which uses an Archimedes screw to carry balls upwards, sorts them into sizes and lets them fall through wacky gadgets, accompanied by sounds and surprises. You could say Techniquest is a gorgeous extravaganza; but hey, why feel guilty about a science centre so designed and coherent?

For a few pence more, you can visit the discovery room, choose an activity box and settle down to something more focused. Here children can work on skulls, rocks, optical illusions, chromatography and more. Then there is the small but perfect planetarium - just enough room to take one class with their teachers and get a guided tour of the stars.

Behind the scenes are a lecture theatre, science lab and an education department that you could call for ideas for your visit. Education director and former head of science Bill Dimes advises that a more structured visit leads to a bigger educational pay-off. To help with this, Techniquest do theme weeks for primary and secondary schools covering energy, forces, sound, materials and even maths and chemistry.

For each topic there are natty “floor walk” question cards for which no pens are needed - the children simply clip their answers as they explore. Yes, it helps to focus. While you are here, in the heart of Cardiff Docks, you can stroll around this fascinating area where the old is mixed with new, or visit the Norwegian church, or visit the fish restaurant.

Bill Dimes would like a visit to a science centre to be something like that. “In the United States, visiting science centres has become a thing to do, like going for a meal, a match or the opera. We’d like Techniquest to at least affect people’s attitude towards science, so that it, like music and sport, becomes an important part of the culture.”

* To mix science with un petit peu de travel, visit the extraordinary Paris science museum, La Cite des Science et de l’Industrie. Five to 12-year-olds can mingle with live ants and butterflies, do a weather show in a TV studio, and see their own beating heart. Younger ones can put on hard hats and build a house with foam blocks and cranes, assemble a car in a garage or make flour from grain. It’s good ideas with child-centred style.

For the rest there are days’ worth of stimulation: a perception gallery where your eye-movements are tracked as you watch advertisements, a Techno Cite full of computers and bicycles. And never mind the thrills from the wrap-around Imax cinema screen, or the moving cinema with seat-belts, this is science avec beaucoup des knobs on.

Take a tip: * Take up your centre’s offer of a pre-visit. Book this and you may get in free.

* Use the visit to see how the exhibits tie in with work at school * Use the centre’s education officer, ask for advice and ideas.

Hands-on centres

Inspire, St Michael’s Church, Coslany Street, Norwich. Tel 01603 612612.

Its special exhibition on Risk runs until October 25 and contrasts the risks involved in climbing sports, running a nuclear power plant and winning the Lottery. Adults Pounds 2.50. Children Pounds 2. Under-threes free. Open Tuesday to Sunday.

The Exploratory, Temple Meads, Bristol, BS1 6QU.

Open seven days a week from 10-5. Admission Pounds 4.75, children Pounds 3.25. Family ticket Pounds 14. Rail: Temple Meads station. Road: Follow the brown tourist signs. NCP Car park. Information line: 0117 907 5000. Bookings 0117 907 9000.

Internet: ww.exploratory.org.uk Snibston Discovery Park, Ashby Road, Coalville, Leicestershire, LE67 3LN.

Tel: 01530 510851. Exhibition Hall: Adults Pounds 4. Concessions Pounds 2.75. Family ticket Pounds 10. Admission to the grounds is free. About 10 minutes from the M1 J22, follow the brown tourist signs. Free car park.

Xperiment! is at The Museum of Science and Industry in Manchester, Liverpool Road, M3 4FP.

Tel: 0161 832 2244.

Open daily 10-5. Admission to entire museum Pounds 4 with Pounds 2 concessions. Under fives go free. Car park Pounds 1.50. Well signposted: follow the brown tourist signs to Castlefield near the city centre. Rail: Deansgate station.

Techniquest, Stuart Street, Cardiff, CF1 6BW. Tel: 01222 475475.

Open daily. Admission Pounds 4.50 with Pounds 2.50 concessions. Family Pounds 11.50. Discovery room and Planetarium 50p extra each. Under fives go free. Leave the M4 at J33 and follow signs to Cardiff bay and Techniquest.

Car park free. Rail: Cardiff Central and short bus or taxi ride.

La Cite des Science et de L’Industrie 75930 Paris, cedex 19, France. Packages via Eurostar through school travel agents and Cresta Holidays. Tel: 0161 929 0000. Internet: http:www.cite-sciences.fr Tel: 00 33 1 40 05 80 00