Stunning sights: from the plesiosaur (not a dinosaur at all) to the modern world. Credit: FROM THE KINGFISHER BOOK OF PLANET EARTH

If you need to make a tricky decision quickly, co-opt a nine-year-old. With the unnerving decisiveness of youth, my co-reviewer took less than five minutes to select her winner among the six books on the shortlist for the under-14 category of the annual Aventis science book prize (see Box, below). The adult judges who chose the shortlist handed over to pupils aged 8–14 from 31 UK schools to select a winner. The professional help thus enlisted, from a population not only unaware of the concept of charging by the hour but temperamentally alien to it, coughed up a winner in short order, undoubtedly avoiding the hours of solemn deliberations that adults feel is necessary before making decisions.

One of the finalists, The Usborne First Encyclopaedia of Our World, is comprehensible to a four-year old, whereas some of the others deal with concepts fairly challenging even for a secondary-school student, older than 11. The younger child loves being read almost anything by an adult, but the encyclopaedia format is probably not optimal for this age-range compared with a sustained but short narrative. So my advice for next year is to narrow down the categories: the under-7, 8–11 and 12–14 age groups are diff erent species. Older readers may well find the Usborne book too simplistically presented compared with Kingfisher's entry on a similar topic.

It's a tradition that children's non-fiction needs a disguise to compete with the popular-fiction likes of Goosebumps. Hence this shortlist's The History News in Space, which tells “the enthralling story of the Russian and American space race this century” as tabloid newspaper journalism in exciting bite-size portions — with boxes explaining concepts such as Newton's third law as well as (disappointingly, spoof) ads for souvenir flight badges and other merchandise. Although this might be rather fun to an adult, it is unclear how the young reader is supposed to distinguish the factual entries from the fictional ones.

Two other titles fall into the teaching-by-stealth category by packaging themselves as joke books: both are cheap, black-and-white paperbacks and so are instantly appealing to the target age-group. One is Evolve or Die (see Box). The other, Brainwaves in the Bedroom, purports to be about magic but is really about neuroscience. Far more editorial guidance is necessary to help the reader tell the pseudo from the science, a distinction difficult enough for many adults.

DK Guide to Space and The Kingfisher Book of Planet Earth are firmly in the traditional mould, both beautifully illustrated, large-format hardbacks with a new subject on each page. The Kingfisher book is a stunningly presented account of the history of our planet, full of wonderful colour drawings with photographs used relatively sparingly. The text is written with an attractive blend of fact and enthusiasm by Martin Redfern — the opening states “Five billion years ago, there was no planet Earth and no Sun. But the Universe was already in full swing”. He continues in this vein with clear, engaging explanations of the history of the planet: volcanoes, earthquakes, geology, origins of life and, finally, a beguilingly didactic last page entitled “The end of the Earth”, stating the four most likely ways in which annihilation will occur. A few pages of useful data and a glossary finish the book off neatly. This one is my favourite, for its accessible style and for getting to grips with topical problems such as anthropogenic climate change and declining biodiversity. Adults buying this book for their children won't be able to stop themselves reading (and learning from) it, too.

DK Guide to Space has big photographs and not many words on topics such as “star birth”, “eclipses” and “man on the moon”. The text is unambiguously informative: jokes and tricks have no place here. Peter Bond writes simple, clear, even poetic explanations: “A vast frozen ocean completely covers the moon Europa. When sunlight catches its icy face, Europa is a dazzling white.” Only one page of data at the back, but this is bang up to date with a table of website addresses for the reader stimulated by the book to find out more. It clearly stimulated the young judges, since this was the one they chose as the winner.