Once upon a time, as Bill Gates of Microsoft is quoted as saying recently, there were only two noteworthy encyclopedias on the market: the Encyclopaedia Britannica and the World Book Encyclopedia.

Indeed, the 22-volume set of the World Book Encyclopedia sells more copies worldwide to the educational and family market than any other encyclopedia. For generations, its staff in Chicago has been, through careful research, supplying information in a format that is educational both for adults and for children working at home and at school. Its editors have consulted educational psychologists, teachers and children, to find out how and what people search for in the way of information, and how best to present it.

As a result, World Book has developed an encyclopedia whose content and illustrations accurately reflect the user’s needs. So successful has the encyclopedia been that its chiefs in the Windy City, like the good rulers in the fairy tale, felt assured that their kingdom, through its excellence, was unassailable.

But Bill Gates, like the fairytale giant, has arrived with an insatiable hunger for business. Belatedly, the regents of Britannica and of World Book realised that in order to survive, they had to equip themselves with the same powerful tools, in particular CD-Roms.

The first multimedia version of the World Book Encyclopedia on CD-Rom came out two years ago. This month sees the launch of the third edition which is over a third as long again as Bill Gates’s own Encarta multimedia encyclopedia. It claims to have the fastest search engine in the world, able to pinpoint and display the information requested in a split second. Its interface, showing the control bar and function icons, is both attractive and self-explanatory.

Moreover, extracts from articles can be pasted on to a clipboard and printed selectively. Years of editorial experience and consultation with teachers have led World Book to create a network of more than 60,000 key links between articles. That is, cross-references are made not just by arbitrary word association of names or of nouns, as in most other multimedia encyclopedias, but also by the important concepts underpinning each entry.

A comparison of multimedia encyclopedias on the market today shows that most have resorted to injecting distractions such as “information tours”, games and random browsing (termed “funformation” by the trade, and intended to be addictive).

By contrast, World Book has not only carried its formula of short, elegant sentences and information-packed illustrations into its multimedia encyclopedia, but has in addition included guidelines to help teachers and pupils work through the national curriculum.

A book, the National Curriculum Guidelines, is available free on request with each copy of the CD-Rom encyclopedia and lists the attainment targets of every level from 1 to 10 of the curriculum, together with the names of the articles in which the user will find the information explained.

As may be expected from an educational publisher, most of the 6,000 illustrations are teaching tools that go beyond such questions as “What does it look like?” to answer the many “hows” and “whys” taught in schools. Multimedia is exploited to its best advantage in the visual animations that explain complex scientific concepts, and in the photographs and beautiful drawings of natural phenomena.

Characteristically, World Book offers the highest-quality multimedia: its superb picture reproduction employs a higher pixel-resolution on screen, and its enhanced sound quality uses a wider frequency band and less audio-compression than its competitors.

Multimedia really comes into its own when it explains, as it does here in animated form, the flight of a bird or the process of chemical attraction in DNA molecules, or shows a video of a young ballet student demonstrating dance movements.

The only reservations that a British user might have is that, until the international edition of this CD-Rom is issued later this year, the emphasis, especially in the multimedia coverage of 20th-century history, remains disproportionately focused on the United States.

A dictionary of over a quarter of a million terms, giving English and American usage, may be accessed from any part of the encyclopedia.

World Book has guidelines on the use of grammar and, uniquely among these encyclopedias, on how to write effective letters, research and present projects and reports, practise first aid and preserve the environment.

The battle lines have now been drawn between the finely-trained lieutenants in Chicago and Bill Gates in Seattle, with the territory in dispute stretching across the classrooms and homes of the world.

* World of Education - stand C61