Thinking in spatial terms is essential to knowing and applying geography. It enables students to take an active questioning approach to the world around them and ask what, where, when, and why questions about people, places, and environments. Thinking spatially enables students to formulate answers to critical questions about past, present, and future patterns of spatial organization to anticipate the results of events in different locations, and to predict what might happen given specific conditions. Spatial concepts and generalizations are powerful tools for explaining the world at all scales, local to global. They are the building blocks on which geographic understanding develops.

Thinking in spatial terms means having the ability to describe and analyze the spatial organization of people, places, and environments on Earth’s surface. It is an ability that is central to a person’s being geographically literate.

Geographers refer to both the features of Earth’s surface and activities that take place on Earth’s surface as phenomena. The phenomena may be physical (topography, streams and rivers, climates, vegetation types, soils), human (towns and cities, population, highways, trade flows, the spread of disease, national parks), or physical and human taken together (beach resorts in relation to climate, topography, or major population centers). The location and arrangement of both physical and human phenomena form regular and recurring patterns.

The description of a pattern of spatial organization begins by breaking it into its simplest components: points, lines, areas, and volumes. These four elements describe the spatial properties of objects: a school can be thought of as a point, connected by roads (which are lines) leading to nearby parks and neighborhoods (which are areas), whereas a lake in a park can be thought of as a volume. The next step in the descriptive process is to use such concepts as location, distance, direction, density, and arrangement (linear, grid-like, random) to capture the relationships between the elements of the pattern. Thus the U.S. interstate highway system can be described as lines connecting points over an area—the arrangement is partly grid-like (with north-south and east-west routes as in the central United States) and partly radial or star-shaped (as in the highways centered on Atlanta)—and the pattern of interstates is denser in the East than it is in the West.

The analysis of a pattern of spatial organization proceeds with the use of such concepts as movement and flow, diffusion, cost of distance, hierarchy, linkage, and accessibility to explain the reasons for patterns and the functioning of the world. In the case of a physical pattern, such as a river system, there is a complex hierarchical arrangement linking small streams with drainage basins and large rivers with drainage basins that are the sum total of all the drainage basins. There are proportional spatial relationships between stream and river length, width, volume, speed, and drainage basin area. The gradual changes that can occur in these properties of a river system are related to climate, topography, and geology.

Central to geography is the belief that there is pattern, regularity, and reason to the locations of physical and human phenomena on Earth’s surface and that there are spatial structures and spatial processes that give rise to them. Students must be encouraged to think about all aspects of the spatial organization of their world. Understanding the distribution and arrangement of Earth’s physical and human features depends on analyzing data gathered from observation and field study, working with maps and other geographic representations, and posing geographic questions and deriving geographic answers.

Spatial relationships, spatial structures, and spatial processes are simple to understand, despite their apparent unfamiliarity. For example, the spatial organization of human settlement on Earth’s surface is generally a pattern of a few large cities which are widely spaced and many smaller towns, which are closer together. A comparative analysis of those cities and towns shows that cities offer a wide range of goods and services whereas small towns offer fewer goods and services. Taken together, the description and the analysis explain why consumers shop where they do, why they often buy different products at different locations, and also why changes occur in this spatial pattern.

Understanding patterns of spatial organization enables the geographically informed person to answer three fundamental geographic questions: Why are these phenomena located in these places? How did they get here? Why is this pattern significant? Description and analysis of patterns of spatial organization must occur at scales ranging from local to global. Students confront a world that is increasingly interdependent. Widely separated places are interconnected as a consequence of improved transportation and communication networks. Human decisions at one location have physical impacts at another location (for example, the decision to burn coal rather than oil in a power plant may result in acid rain damaging vegetation in a location hundreds of miles away).

Understanding such spatial linkages requires that students become familiar with a range of spatial concepts and models that can be used to describe and analyze patterns of spatial organization. This knowledge can be grounded in the students’ own immediate experiences, and yet it will give the students the power to understand the arrangement of physical and human geographic phenomena anywhere on Earth.