Thematic Maps

Thematic maps are maybe the most used maps when it comes to data. They encompass a vast variety of maps including but not limited to dot distribution maps, chloropleth maps, and isoline maps. The unifying characteristic of these maps is that they all convey data on a topic superimposed onto an original basemap. For example the map above, has unemployment data classified into different groupings over a base map of the counties of Missouri.

http://www.oseda.missouri.edu/articles_chron.shtml