1.2 Geographic Data

Field data is information collected in person, at the place being studied. Individuals collect it, such as a student counting pedestrians at an intersection or a researcher interviewing farmers. Organizations collect it too: government agencies like the U.S. Census Bureau, nonprofit groups, universities and businesses all run surveys and counts.

Common field methods include observation (watching and recording what happens), surveys (the same questions asked of many people), interviews (longer conversations with fewer people) and landscape analysis (reading what buildings, signs and land use reveal about a place).

• Satellite navigation systems find an exact location using signals from satellites. GPS is the U.S. system; Europe's Galileo, Russia's GLONASS and China's BeiDou work the same way. Your phone's location, delivery tracking and precision farming all depend on them.
• Remote sensing collects information about Earth from a distance, using satellites, airplanes or drones. The U.S. Landsat satellites have photographed Earth's surface since 1972, which lets you compare how a forest or city has changed over decades.
• A geographic information system (GIS) is software that stores data in layers tied to locations, so you can stack them and look for relationships. For example, you could layer flood zones, hospital locations and population density to find neighborhoods at risk and far from care.
• Online mapping and visualization tools, like web map apps and interactive dashboards, let anyone view or build maps. Some, like OpenStreetMap, are built by volunteers who add data themselves.

Not all spatial information is numbers on a map. Geographers also learn about places from field notes, news reports, travel narratives (accounts written by travelers), policy documents like zoning laws or immigration rules, personal interviews, and photographs. A photo of a street can show the language on signs, the style of buildings and how crowded it is.

These sources are useful, but each has a point of view. A travel narrative tells you what one outsider noticed, and a government report reflects what that government chose to measure.

Quantitative data is anything you can count or measure, like population, rainfall or income. It is good for comparing places and spotting patterns on a map. Qualitative data is descriptive, like interview answers, photos or observations about how people feel about a place. It is good for explaining why a pattern exists and what it means to the people living there. Strong geographic research usually uses both.