Want to know all about goats? Maybe not, but William Hartston finds they're a good test of an interactive encyclopedia
A couple of years ago, Oxford University Press produced two CD- Rom titles - Oxford Compendium and Oxford Reference Shelf - each with a variety of reference titles on a single disc. Although the search mechanism was effective enough, and the contents were of OUP's usual high standard, moving from one reference work to another was confusing and liable to produce a repetition of material when you jumped from, for example, the Dictionary of Quotations to the Dictionary of Modern Quotations.

The new Oxford Interactive Encyclopedia is a similar amalgam of existing OUP encyclopedias and dictionaries, but joined together so wellthat you can hardly see the seams. In the spirit of good infotainment, there are also about 80 video clips and animations. For pounds 39.99, this is outstanding value.

Before rushing out to buy it, however, you should think carefully about whether to invest another pounds 10 and get the World Book Multimedia Encyclopedia UK edition from IBM, at pounds 49.99. As well as containing all 22 volumes of the printed version and a two-volume dictionary, it includes an entire extra diskful of video and animated simulations, intelligently indexed from the main disc to avoid the irritation of too much disc-swapping.

To compare these two encyclopedias, I decided to see what they could tell me about two topics of current interest: goats and the number 103.

The Oxford Interactive told me there are 26 species of goat, and the animal was domesticated around 7,500 BC. It also provided pin-up photos of the angora goat, the Rocky Mountain goat, a Pehul shepherd with goats, Big Goat Lake in Alaska and Goat Fell on the Isle of Arran (misspelt "Arron" in the caption). Then it gave me a guided tour of the new Globe Theatre, which, as far as I could tell, had no relevance to goats. I went on, however, to learn about the goat moth (which has large, wood- boring caterpillars that smell of goats), goat-face grass, and the European nightjar or "goatsucker". I was also led, for no discernible reason, to a goatless list of soft drinks.

The World Book provided pictures of the Nubian goat, Toggenburg goat and bezoar goat, then told me about cowgirls in a goat-tying event at rodeos, goat water (the national dish of Monserrat), Amalthea (the goat that nursed Zeus as a baby and whose horn, cornucopia, produced ambrosia and nectar), the Phoenicians who, in 600 BC, made soap from goats' fat and ash, and William Francis King, the "Flying Pieman", who carried a 42kg goat from Sydney to Parramatta in seven hours for a bet.

The Oxford Interactive told me there were about 103 species of crow, 103 days a year the mistral wind blows and 103 days that China's "Hundred Days Reform" lasted in 1898. The World Book fought back with the 103 people per square kilometre in south-east Asia, 103kg maximum recorded weight of a mountain lion and 103kph that a wind has to be to reach storm force on the Beaufort Scale.

These are both superb products at low prices, but for wider coverage, more up-to-date material and greater reliability of search results, the IBM World Book is well worth the extra tenner.

Oxford Interactive Encyclopedia (pounds 39.99, The Learning Tree); World Book Multimedia Encyclopedia (pounds 49.99, IBM).