The advent of scientific investigation carried out by pupils as a large, compulsory part of the national science curriculum may have reduced the number of demonstrations done by science teachers, but thankfully has not removed them entirely from school science labs. For the reflective science teacher, the use of eye-catching demonstrations for illustrating phenomena, arousing curiosity or interest in science has always had its place.

However, some demonstrations can often be too dangerous, too time-consuming or just too expensive to set up in a typical science lab. This is where a collection of 600 multimedia demonstrations on disc can be a godsend, to complement the ones you can do on the front bench.

The Video Encyclopedia of Physics Demonstrations was previously only available on Laserdisc. In this format it has (according to its makers) been used to teach physics at over 2,000 high schools and universities in the US and in 40 other countries throughout the world.

Now, the first DVD edition of The Video Encyclopedia of Physics Demonstrations has been completed and preview discs are available for teachers to judge it for themselves. The discs contain a comprehensive series of 600 videotaped physics demonstrations, produced, in part, under a grant from the National Science Foundation in the US. Each of the 600 demonstrations is concisely produced and narrated; each stands alone and illustrates a particular principle of physics.

The demonstrations, about 10 hours in length and now mastered to 25 DVDs, are augmented by slow-motion photography and animation and allow for interactive participation by students, including calculations which can be done “off the screen”.

The DVDs are also accompanied by books of written material which include scripts, explanatory material, illustrations and a list of equipment for each of the demonstrations. The demonstrations are also linked to popular text books, but these are very much US texts.

Despite the US origins, almost all of the material is valuable to physics teaching in the UK. The content of the demonstrations covers the core areas of A-level syllabi and many optional topics.

As is true with many CD-Rom resources, the discs can be used lower down the school, but in a different way. For example, they could be used simply to show different phenomena without going into detail or becoming quantitative, eg all sorts of examples of motion could be shown - water rockets, a bed of nails, Galileo’s pendulum, a clown on a rope, a guinea and feather falling at the same rate on the moon etc. Teachers could show these without using any of the ommentary or going into detailed explanations.

Many of the demonstrations are directly relevant to the England and Wales national curriculum.

Can these discs help students to learn science and - the most valuable science resource - the teacher to teach it? The answer is “Yes”. All the demonstrations are clear and are not carried out by the stereotypical scientist in a white coat. The demonstrators are of student age as well as being balanced in terms of gender and ethnicity. The physics is sound and, most importantly, all the experiments work.

One of the strengths of disc over tape is their interactivity - students can speed up, slow down, freeze or reverse the video to their heart’s content and at their own pace. Another way of learning is the “What happens next?” strategy, made famous by the BBC TV quiz programme, A Question of Sport. Students can see some action, then pause while they are asked: what happens next? The demonstration will then, after a suitable time, go on to show them. This allows for the “predict-observe-explain” mode of teaching which is so valuable in science education.

The educational value of this resource is evident, but what about the technology delivering it? The material has already travelled along one technological cul-de-sac in its previous life on Laserdisc - is it ahead of its time by going for DVD? My own amateur survey this week indicates that few schools will have ready access in their science departments to the hardware needed to run this material - and the ICT co-ordinator, who may not always be the science department’s best friend, may not have a central solution (and certainly not a networked one).

However, they can be used on a school TV with a cheap domestic DVD player. PC access is particularly useful for teachers for the back-up text materials.

Some of the luckier, and more affluent students may be able to use it on computers at home but this is hardly a fair solution and would probably not warrant an outlay of $2,995 (about pound;2,125) for the whole package.

Imagination will be needed if the educational value of this resource is to be realised - it will be a loss to science teaching at a critical time if material like this cannot be exploited as part of a science education.

Jerry Wellington is a professor in the School of Education at the University of Sheffield, UK The Video Encyclopedia of Physics Demonstrations from The Education Group. Contains 600 demonstrations and 3,000 pages of written material on 25 DVDsPrice: $2,995 (around pound;2,100 - + $89.95 shipping to the UK)Available from The Education Group, PO Box 1667-90069, Los Angeles, CA 90069, USATel: (+01) 310 276 1122Fax: (+01) 310 276 7330Email: physics@edgroup.orgwww.physicsdemos.com