Unclassed choropleth maps

 http://euclid.psych.yorku.ca/SCS/Gallery/milestone/sec5.html

This is an unclassed chloropleth map. It shows the rates of illiteracy in France from 1800-1849. Unclassed chloropleth maps use a scale without assigned values to create a map which tells which areas are better and worse, but not assign any specific values to those claims.