Guidelines
Suggest edit

Use maps or geo-referencing when location matters

For explanation or comparison where geographic scope is part of the message, use maps or geo-referencing on place-based data displays to improve spatial understanding and address missing place context for readers relating data to known places.

  • purpose:refine
  • basis:rhetorical
  • chart:map:use
  • data:geospatial
  • reading-mode:overview
  • quality:insight
  • lever:encoding

advice

Geographic reference

Use a map or explicit geo-referencing when the message depends on where things happen. For example, show place-based issues as maps to give a geographic overview, and geo-reference country comparisons so readers can connect values to known places.

reason

Why geographic reference helps

Geographic reference gives readers a place-based overview instead of leaving them to infer location from labels alone. That makes it easier to see the area covered, relate the display to familiar places, and read the visualization as awareness-raising or decision-support when geography is central to the message.

Mechanism: Mapping data to recognizable places helps readers orient themselves spatially, understand geographic scope, and connect the message to places they already know.

Evidence: Viewers commonly interpreted crisis maps as geographical overviews that raised awareness and could support decision-making (Koesten et al., 2025). Practitioners reported that readers strongly preferred maps and that country-level comparisons worked well in their usage metrics (Schuster et al., 2023).

Notes: Different readers may infer different purposes from the same map, but they still tend to read it first as a geographic overview.

context

Use when place is part of the message

  • User Goal: Show where something is happening or what geographic area the topic covers.
  • Task: Orient readers to locations or compare places such as countries.
  • Data: Values are attached to places, regions, or countries.
  • Chart Setting: The display needs to communicate a geographic overview, not just isolated values.
  • Audience: Readers can relate the data to known places.
  • Success Criterion: Readers can identify the places involved and the overall geographic scope from the visualization itself.

exceptions

Do not use when geography is not doing explanatory work

Break it when: The message does not depend on location or geographic scope. Why: The map or geo-reference is no longer supporting the main interpretation.

costs

Tradeoffs of geographic framing

Sacrifice: The display emphasizes geographic overview as a primary reading. Risk: Viewers may interpret the display as awareness-raising or as a decision-support view, not only as a neutral data graphic. Mitigation: Use the map or geo-reference only when that geographic framing matches the intended role of the visualization.

mistakes

Common failure around geographic reference

Mistake: Leave place-based data un-georeferenced even though the message depends on location. Why it fails: Readers lose the geographic overview and have less support for relating the data to known places.

check

Review for geographic orientation

Failure Sign: Reviewers cannot tell what area the display covers or which places are involved without extra explanation. Quick Check: Show the visualization on its own and ask a reviewer to name the places or area it covers. Stronger Test: Compare the current version with a mapped or geo-referenced version and keep the version that more clearly reads as a geographic overview.

fix

Edits to add place context

  • Convert the display to a map when the main message is where events or values occur.
  • Add geo-referencing so each value is tied to a recognizable place.
  • For country-level comparisons, show the countries in geographic context rather than leaving the comparison unlocated.

References

Koesten, L., Saske, A., Starchenko, S. M., & Gregory, K. (2025). Encountering Friction, Understanding Crises: How Do Digital Natives Make Sense of Crisis Maps? Proceedings of the 2025 CHI Conference on Human Factors in Computing Systems, 1–15. https://doi.org/10.1145/3706598.3713520
Schuster, R., Koesten, L., Möller, T., & Gregory, K. (2023). Who is the Audience? Designing Casual Data Visualizations for the “General Public.” arXiv. https://doi.org/10.48550/arXiv.2310.01935