Review: Geographic Information Systems (GIS) have been with us for some time but until now they have been kept mainly to the realms of academia. The advent of programs such as WorldWind and Google Earth has brought spatial awareness to mass audiences. Add the range of mashups (linkages of data and maps often from different sources) that are available as well as sites offering to host spatial data and you have the ingredients for a revolution in spatial awareness amongst the general public. Today it's important that we emphasise the value of GIS not just in terms of ecological and environmental education but also in terms of wider community use.

When this book was first published in 1998 the introduction above might have seemed far-fetched. Today, we need to use this new technology to improve not only education but the environment as well. Despite the increasing interest in GIS (even the journal Nature has devoted space to extolling GIS's virtues to education) there would still be a need to learn more about the basics of the system. This third edition is well placed to capitalise on this recent interest. The book is divided into two sections dealing with fundamentals and issues. The first section, looking at fundamental aspects starts, appropriately enough with an overview of what GIS is (and is not) and what it can do (and can't!). It sets the scene for the material to follow. Chapter two focusses on the types of data that can be used in GIS and how this can be output. This might seem abstract but it is fundamental to the process. One could make the analogy with a car - it's possible to drive knowing nothing about the mechanics but it's far better to see how it works and when it might not. Chapter three looks at how data can be output as either raster or vector along with more advanced techniques. From this we move to the database to see how it is structured. Chapter five takes the process one stage further to explore how data can be input into the system (often the slowest part and one where student interest might flag) as well as the range of outputs that can be obtained. The last three chapters in this section focus on the business end of GIS - getting the data out. Here is the really interesting part - data can be input into the GIS but it is the system's ability to rapidly restructure parameters and alter answers that makes it so invaluable to all areas of our work from management to science. Previously such data were available and would be put onto maps. Overlays could be added and then key areas extracted manually according to need. GIS does away with all this by virtue of its processing capacity and ability to more accurately interrogate the data. Part two looks at some of the issues that have been raised about GIS. Although it is "just" a computer software package its ability to affect our decision making in profound ways is such that we need to be aware of some of the surrounding debate. Thus chapter 9 shows how we got into this situation via paper maps and how this influences our thinking. Chapter 10 describes the range of data errors that can plague GIS - it's ability to handle large data sets is also its main weakness: huge quantities of poor data is still a poor result however much the program manipulates it. Chapter 11 scales up the issues from individual users to corporations and shows what needs to be considered. Next, we see how GIS can be brought into management although, as it's made clear, we need to know what we are looking for first. A final chapter discusses the future of GIS.

There is much to admire in this text. Alongside the information about GIS there's a wealth of educational input that makes the text one of the best teaching aids in this topic area (as one would expect from authors with key distance learning experience). Each chapter has a series of educational aids - outcome lists, a range of text boxes to focus on key areas or features (theory, case studies, reflection areas, questions, references and web resources). In addition, there's a book website with quizzes, a glossary, student and teacher sections (the latter yet to be implemented). Overall, a very impressive aid to understanding and one that deserves a wide readership.