With a sigh of relief you'll note that crucial word 'practical' in the title and sharpen your coding pencil to get stuck into some expert designing. Sharpen your wits first. There are scene-setting chapters and enough contextual information to sink a ship before you reach the practical work.

Don't be put off by the assertion early on that "this is an engineer's book". An engineer in this field means a software engineer, which is just a fancy word for a programmer who takes the work seriously.

The greater part of the book, though, concentrates on the practical aspect, using the authors' own general system called innocently Expert. There is a touch of old-world academic charm about this, but nothing so patronising as a listing. The expert system you create will be your own - Expert is used merely to point the way. The authors then illustrate the lesson with several applications, and finally look ahead to the implications of the kind of research area in which by now you should count yourself a co-worker.

This is not the best book on expert system design, nor the most accessible, nor the most direct. But it is a serious attempt at a serious subject and you're unlikely to consider your money wasted.

David Guest