Geographic Data
Geographers don't just look at maps — they collect the data that goes into them. Knowing the difference between qualitative and quantitative data, and between GPS, GIS, and remote sensing, is a recurring source of exam questions.
Quantitative data is numerical and measurable — a population count, a temperature reading, a percentage. Qualitative data is descriptive rather than numerical — an interview about how a neighborhood feels to live in, a photograph, an oral history. Neither is more “correct” than the other; they answer different kinds of questions.
The most direct way governments collect quantitative data about their population is a census — a comprehensive, periodic count. Geographers also go directly into the field for a field study, observing and interviewing on-site to gather both qualitative and quantitative data a census or satellite could never capture.
Three geospatial technologies get confused constantly, so keep them separate: GPS (Global Positioning System) uses satellites to pinpoint an exact location — it answers “where am I?” Remote sensing gathers images and data about the Earth’s surface from a distance, usually via satellite or aircraft, without anyone physically visiting the site. GIS (Geographic Information System) is software that layers multiple data sets — population, zoning, flood risk, whatever’s relevant — on top of a single map to reveal how they relate. GPS locates, remote sensing observes from afar, and GIS analyzes by combining layers.