Choropleth story maps in 1826: Shared baseline

When should I avoid Choropleth story maps? Skip it in cases like: raw counts without normalizing by population or area. Baron Charles Dupin (1826); modern TopoJSON + D3 geo pipelines color of administrative regions mapped to a quantitative rate Yes if one claim is visible at a glance in Meta, Google and retail print; otherwise link to a full figure.

Yes for lab reports and poster boards if axes, units and a source line are present. Excel or Google Sheets or PowerPoint; export SVG/PDF. Do not rely on hue alone. Label directly and check greyscale. Choropleth story maps: honour color of administrative regions mapped to a quantitative rate, and switch when raw counts without normalizing by population or area.

The core mark of Choropleth story maps is color of administrative regions mapped to a quantitative rate. regional comparisons, civics assignments, territory KPIs The eye compares length and position more accurately than area. PowerPoint, Excel or Google Sheets and Meta, Google and retail print share the same geometry.