and rivers on a world map, and geographic instruction is often equated with conveying information about remote parts of the world. From this perspective it may be a surprise to some that the discipline of geography has a great deal to say about many of the critical issues facing society in the late twentieth century.
Geographers are engaged in valuable research and teaching on matters ranging from environmental change to social conflict (see Chapter 2). The value of these activities derives from the discipline's focus on the evolving character and organization of the Earth's surface; on the ways in which interactions of physical and human phenomena in space combine to create regions with distinctive natural and (or) social characteristics, or places; and on the influences those places have on a wide range of natural and human events and processes. Such concerns are not simply exercises in expanding the encyclopedic knowledge of faraway places; they go to the heart of some of the most urgent questions before decision makers today.
A central tenet of geography is that "location matters" for understanding a wide variety of processes and phenomena. Indeed, geography's focus on location provides a cross-cutting way of looking at processes and phenomena that other disciplines tend to treat in isolation. Geographers focus on "real world" relationships and dependencies among the phenomena and processes that give character to a place. Geographers also seek to understand relationships among places: for example, the flows of peoples, goods, and ideas that reinforce differentiation or enhance similarities. In other words, geographers study both the ''vertical" integration of characteristics that define place and the "horizontal" connections between places. Geographers also focus on the importance of scale (in both space and time) in these relationships. The study of these relationships has enabled geographers to pay attention to complexities of places and processes that are frequently treated in the abstract, if at all, by other disciplines.
Geography's perspectives are supported by a body of distinctive techniques for observation, such as field exploration, remote sensing, and spatial sampling, and for the analysis and display of geographic data, such as cartography, visualization, spatial statistics, and geographic information systems (GISs; see Chapter 4). These techniques are shared with other disciplines, but geography has contributed fundamentally to their development and improved application.
The traditional tool in geography for the display of spatially referenced information is the map. To many, the term "map" connotes a fixed, two-dimensional paper product containing point, line, and areal data. During the past generation, however, advances in data collection, storage, analysis, and display have made this traditional view obsolete. The modern map is a dynamic and multidimensional product that exists in digital form, opening up new areas of research and application for geographic investigation. This research has led to the development of GISs, which, along with techniques for geographic visualization and methods of spatial analysis, facilitate an increasingly complex and contextual understanding of the world. Current research in GISs is expanding