MAPS / PRACTICAL GUIDE
Choropleth map: examples and when to use it
A choropleth map colors geographic areas according to a numeric measure. It reveals regional patterns while preserving the shape and location of each area.
When to use it
Use it for regional rates, shares or densities. A raw total can be mapped when that is the intended question, but larger populations and areas can dominate comparisons.
When to choose another view
Use proportional symbols when comparing quantities at locations. Use a bar chart when precise ranking matters more than spatial pattern.
How to read it
Read the legend before the colors. Each shade represents a range or value, not the physical size of an area. Large regions occupy more visual space even when their population is small.
Data format and example
A region identifier and numeric measure per region. Match names or codes to the selected boundary dataset; keep missing values distinct from recorded zeros.
| Province | Revenue | Exposure |
|---|---|---|
| West Java | 120 | 45 |
| Central Java | 95 | 70 |
| East Java | 130 | 60 |
| Bali | 0 | 20 |
| DKI Jakarta | Missing | 90 |
Make it in Datamon
- Choose the geography and administrative level that match your data. Review unmatched names before interpreting the map.
- Map the region and measure columns. Resolve ambiguous names with a code or explicit match rather than a guessed location.
- If your question compares risk or intensity, compute an appropriate rate using a relevant denominator before mapping.
- Choose a classification and inspect its legend. Quantiles compare rank groups; equal intervals compare fixed numeric ranges. Show the unit and source.
Common mistakes to check
- Blank regions are not zero-value regions. Keep a separate no-data appearance.
- A map of counts and a map of rates answer different questions. State the denominator when using a rate.
- Changing class boundaries can change the apparent pattern. Compare distributions before selecting a palette.
Further reading: Esri on choropleth normalization.