You can only guess that when Dorling Kindersley brings out a new version of its general science encyclopedia it is a measure of past success. It is a measure of demand too: the attraction of covering the three sciences and maths on one disc is as irresistible in teaching as it is in the home learning market.

Encyclopedia of Science version two is a broad sweep, with nearly 10 times more material than the original. There’s a Matter Explorer which enables you to take either a leaf, an aphid, a piece of metal or a nylon sock and magnify it in stages until the only thing you can see is atoms. That’s good. So are the very handy bits of animation showing electrolysis, gases diffusing, coloured light mixing and meiosis - the making of sex cells.

There is indeed extra detail, though the 1,000 new articles don’t give the best explanations of, for example, antibodies, the red shift or reaction rates; you’ll find better in school books. But now and then the pictures or the video of, say, bacteria dividing, add value.

What is unmatched, however, is how easy this CD-Rom is to use: a menu shows the contents as a branching tree; buttons called “See also” and “Find out more” feed your curiosity. That the film index shows tiny pictures or the main menu is a retro-look museum console seems like gimmickry, but if that’s what you have to do to encourage children that’s okay. Finally, all the text is searchable, printable and copiable to a word processor - a real innovation, and handy for those who use computers for project work.

The title is unfortunate because it promises too much, so if you look on it as a course book it has gaping holes. Interestingly, a button on this program connects you to Dorling Kindersley’s Science On-line site on the Internet. Maybe one day this feature will plug all the gaps. But that’s not to dismiss this title; it surely will be useful for revising at home or for reference in the library.