If McGregor and Watt tell you how, Reffin-Smith tells you why. Tutor in Computing at the Royal College of Art and himself a maker of computer-based art and design works, he has produced a stimulating book; if you liked 'Zen and the Art of Motorcycle Maintenance', then this is for you. If on the other hand you want a down-to-earth factual introduction to computer graphics, then look elsewhere. Starting at the back, you will find a glossary, and some useful nuggets in 'Outlines for courses on the use of computers in art and design'. Working towards the front, you'll find interviews with five artists working in the field and accounts of the work of some nine more.

Elsewhere there are excellent descriptions and explanations of what is actually going on - what a computer is and does; but this is not where Reffin-Smith's heart lies. His work is an apologia for soft computing, which he sees as a qualitative activity, to do with art. To avoid its being lumped in with the trivia known as 'computer art' he has coined the word 'meta'. Soft computing is qualitative, conceptual, highly complex, multi-referential, probably political. He teases the reader: what's really going on is always in the next paragraph, the next level down. That's how it really is, with different levels of metaphor instead of one true description.

He examines our notions of what is a work of art, and of creativity, suggesting how it is possible to handle values and qualitative data with a computer. Not at all an easy book, but one which raises a number of interesting ideas.

As a production the book is disappointing: the exotic cover tantalizes like a come-on computer game package: inside the covers is grey text, interspersed with correction lines which have the weight of sub-heads, diagrams apparently off the backs of envelopes and eleven stingy little colour reproductions, none larger than 65mm x 95mm.

All three authors are university lecturers. One used to tell children to 'Do as I say, not as I do', but in the case of these two books it may be easier to do as they do, rather than as they say, and judge the worth of the authors by the Beeb programs that they have written - McGregor and Watt for Addison-Wesley and Brian Reffin-Smith for BBC Publications.