specification to another (e.g., Tobler, 1969). Research is also needed to understand how to separate environmental effects from other geographic variations in health research—how, for instance, to separate environmental factors that cause cancer from the density of susceptible populations when searching for cancer clusters. This last example illustrates the importance of research in addressing important public policy questions.
Current trends in geography's techniques suggest a future in which researchers, students, business people, and public policy makers will explore a world of shared spatial data from their desktops. They will request analyses from a rich menu of options, select the geographic area and spatial scale of analysis, and display their results in multimedia formats that are unanticipated today.
In developing GIS-GVis tools of the future, developers need to think more broadly about the context of the problems and the knowledge and skill levels of users. The users of tomorrow are likely to be a far broader group than at present—in background, perspectives, and skills. Indeed, many will be novices by today's standards, and they will rely on the embedded knowledge of experts in their use of these tools.
The users of the future will also bring different world views and theoretical perspectives to these tools. They will challenge the adequacy of current techniques for analyzing and understanding geographic phenomena, posing challenges that must be taken up by developers when designing next-generation tools and theories.