From Ancient Greek χώρα (khṓra, “location”) + πλῆθος (plêthos, “a great number”) + English map. First proposed in 1938 by American geographer John Kirtland Wright to mean "quantity in area," although maps of the type have been used since the early 19th century.
- A thematic map in which the distribution of some property is shown using different colours.
- 1999, Jeffery T. Walker, Statistics in Criminal Justice: Analysis and Interpretation, page 66:
- The scale and unit of analysis for choropleth maps depends upon the area to be mapped.
- 2004, Gerald R. Pitzl, Encyclopedia of Human Geography, page 29:
- The choropleth map, which shows distributions by area, is one of the most frequently used maps in geography.
- 2013, Ian Muehlenhaus, Web Cartography: Map Design for Interactive and Mobile Devices, page 147:
- As the Mercator is to Web projections, choropleth maps are to thematic cartography (i.e., they are overused).