Geographers study patterns like density and concentration, but where do the facts come from? In GPS, GIS and Satellite Images you saw some of the tools. This lesson sorts the data itself into two kinds and asks what each is good for.
Key idea
Quantitative data are numbers: census counts, incomes, temperatures, satellite measurements of land cover. Qualitative data are words, pictures and observations: interviews, photographs, field notes, travel diaries. Good geography often uses both: numbers show what and where; words and pictures help explain why.
Why it works
A map of numbers can show that a neighborhood lost half its stores in ten years, but not why. Talking with shop owners and residents, or photographing empty storefronts, can reveal causes the numbers miss: a new highway, rising rents, a mall built nearby. Numbers let you compare many places fairly; words and pictures let you understand one place deeply.
- Censuses: counts of a whole population, often every ten years (the U.S. census since 1790).
- Surveys: questions asked of a sample of people.
- Remote sensing: data gathered from satellites, planes and drones, without visiting.
- Fieldwork: observing, measuring, photographing and interviewing on the spot.
- GIS (geographic information systems): software that layers many kinds of data on one map.
Worked examples
Worked example: Choosing data
You want to learn why young people are leaving a rural county. Which data would you gather?
- Quantitative: census counts by age over several decades show how many left and when.
- Qualitative: interviews with young people and their parents show the reasons, such as jobs or schools.
- Together they show both the size of the change and its causes.
Answer: Both: census numbers for the pattern, interviews for the reasons.
Worked example: Is a survey quantitative?
A survey asks, "In your own words, what do you like about this town?" What kind of data does it give?
- The answers are open-ended words, not numbers.
- So they are qualitative, even though they come from a survey.
Answer: Qualitative.
Common mistake
Students think only numbers count as data. Interviews, photos and field notes are data too, collected and recorded carefully. The kind of data depends on its form (numbers or words and images), not on whether it came from a computer or a survey.