Roll up for a roller coaster ride around your virtual body

The human body is a marvellous machine and one that is explored on a number of CD-Roms. Which one should you buy? Body Park is a CD-Rom that sets out to teach health, safety and nutrition to the under-10s. Its format is a theme park shaped like a gingerbread man. The main attractions are the major organs - the heart, the lungs, the brain - but there are also plenty of amusing animations encouraging kids to explore.

A book is displayed inside each of the tents and stalls. All the text is narrated, making this program suitable for pre-readers, and there are lots of animated graphics. Each section has a Fun Facts button containing information that children are likely to find amusing; for example, that the largest muscle in the body is the one you sit on - the gluteus maximus. All the games are useful, and are pepped up by being played against the clock.

The Magic School Bus Explores the Human Body features a class of school kids travelling on a bus round the major organs of the body. At each of the 12 stops there is an on-screen experiment. Discover how the liver deals with fats, poisons, sugar and vitamins or how the kidneys and bladder cope with salt and water. Each location also has a game relevant to the organ visited. For example, there is a falling blocks game where the aim is to line up breakfast, lunch, main course and dessert in the stomach. The commentary is fun, and should appeal to the target audience - children from seven to 10.

3-D Body Adventure comes with special spectacles with red and green lenses for viewing stereograms on the computer screen. You start with a human skeleton, and click your way towards more detail. There is a lot of reference material, and you need to be prepared to do some reading. But the program has a lighter side: in the Emergency Game players have to "cure" four patients by getting inside their bodies and zapping the diseased cells or organs. This activity is aimed at eight- to 12-year-olds while Body Recall, where pictures of body parts have to be matched to their names or descriptions of their function, is for younger users. A few video clips are included. The one described as "a thrilling roller-coaster ride up and down the spine" is little more than a novelty while the ones of the heart and the brain are more informative.

BodyWorks' technical approach makes it suitable only for older users - 12 to adult. It relies on the use of three-dimensional graphics and presents 25 models, including the brain, the heart, the eye and the ear, that can be rotated to allow the user to view them from all sides. There are also 45 video sequences. Some of these, such as the one that shows how the bones of the skull fit together, are animated models, while others are film clips, including a video of childbirth. There is a new section in the latest version 5 called called Dr BodyWorks. This consists of 10 lectures, each lasting a few minutes and covering one of the major organs (the heart, lungs or brain) or a system (circulation, digestion or reproduction). The CD-Rom includes a quiz called Body Basics. It uses a games show format, but the questions are tough - you will win only if you have paid close attention to the material on the disc.

The Ultimate Human Body has no games at all, concentrating instead on providing a lively and comprehensive treatment of the subject matter. Like other titles in the Dorling Kindersley Multimedia series it uses a white background for text and illustrations. There are three "search paths" through the program: Body Machine, which shows how the elements of the body function together and explores fundamental processes such as seeing and hearing; Body Organs with its details of individual components of the body, and Body Systems which shows how organs work together. Only some of the text is narrated, but the excellent animations maintain interest throughout.

3D Body Adventure II, pounds 29.99, Random House New Media, 01621 816900.

The Ultimate Human Body, pounds 59, Dorling Kindersley, 0171-836 5411.

Body Park, pounds 24.99, TecMagik, 0171-486 3202 (Toys R Us).

Magic School Bus Explores the Human Body, pounds 31, Microsoft, 0345 002000.

Bodyworks 5, pounds 47, Guildsoft, 01752 895100.

All prices include VAT.