Univariate Choropleth Map

http://www.clearlyandsimply.com/clearly_and_simply/2009/06/multicolored-choropleth-maps-with-excel.html

Univariate choropleth maps are meant to show only one variable distributed across an area or a region. This map gives a visualization of the different ways people say "soda" in the United States. It shows that it is referred to as "pop" in the north, "coke" in the south, and "soda" in the southwest regions.