Schools: Home Help The first in a series on how to help your children with homework

Non-fiction used not to be sexy. Encyclopaedias were a dry, unforgiving breed of book that demanded perseverance. The world and its contents were presented in an arid, dogmatic, Anglocentric form with only a sprinkling of tables and plates to enliven the text. By the Sixties the illustrations were more numerous but the encyclopaedia's definitive snapshot of the world was usually 20 years out of date: the Empire State was still the tallest building and the Queen was still a blushing young monarch in Coronation robes and the Inuit population was still cutting holes in the ice and doing unspeakable things with blubber.

Today's need for ''relevance'' means that even solid, multi-volume encyclopaedias are being reprinted every couple of years. The revised nine-volume Oxford Children's Encyclopaedia appears in June. Although available on CD-Rom, the print version of this superb work is still just about affordable at pounds 125 and - unlike the CD - can mesmerise several children at the same time. The latest additions are minor but telling: OUP are smugly proud of the fact that the late Princess of Wales will remain eerily alive and well in all other children's reference works.

Not for long she won't. The latest edition of Dorling Kindersley's Children's Illustrated Encyclopaedia (644pp, pounds 29.95, 8-plus) comes out in September and will include Diana's death. Not only that, it will finally pension off the picture of Pink Floyd in the pop music section (although what that lot were doing in a book originally published in 1991 is still a mystery. Good agent I suppose).

Making alterations to text and layout is expensive and Dorling Kindersley's arrangement is designed to minimise disruption. Unlike the Kingfisher Children's Encyclopaedia (800pp, pounds 30, 7-11 years), with its 1,300 entries, DK's volume deals with 450 broader categories a page or a spread at a time. DK made its reputation with picture-led design but it also ties in with its plan for world domination. When the book is translated into French, German, Japanese, Klingon, etc and subsequently realphabetised, it is simply a matter of shuffling pages around rather than devising a fresh layout for each foreign edition. All very convenient but abandoning the dictionary-style approach makes it harder for younger children to use.

The DK one-volume encyclopaedia is intended for eight plus, whereas Kingfisher starts at seven. This may not seem significant but there is a big step between a child who can just grasp the whole "looking it up" concept and the child that is already beginning to understand how subjects are grouped. In W, for example, Kingfisher will already have dealt with Wagner, Wales and Wallaby before DK even gets started with Warships. It's not that DK ignores Wagner, but you'd need to look him up in the 15-page index first.

On balance, a younger child will be better served by the Kingfisher. Every entry is illustrated ("Hormone", cruelly, uses a picture of Willy Carson, the jockey, to illustrate the fringe benefits of a shortage of growth hormone), and major subjects such as the moon or the Middle Ages get their own double-page spread. My six-year-old got the hang of alphabetical order within days and was soon looking up his various obsessions (Ancient Egypt, sharks, vultures), and regularly takes the book to bed.

Many children go through a phase of actually reading encyclopaedias. This is normal. If yours is at this stage, the Collins Children's Encyclopaedia (271pp, a snip at pounds 9.99) is a good bet. The material is arranged thematically, and although this makes it fiddly to look up individual facts, it does make a smoother read for the fact-guzzler.

It's sound stuff, although it lacks the appeal of Dorling Kindersley's 3,500 colour illustrations. DK's pretty pictures are splendidly detailed and annotated and are perfect for browsing, but ultimately the company philosophy boils down to "text bad, pictures good". A DK spokesperson summarised obligingly: "If you give an eight or 10-year-old a page that's mostly text they'll be intimidated or at least less attracted." Maybe they're right. Maybe today's children do have the attention span of a retarded goldfish. But maybe the right encyclopaedia can change all that.

Louise Levene

Next week: History books