A choropleth map uses colors or shading to show differences between areas. Areas that share a quality are colored or shaded alike. A very simple choropleth map of the United States could be made using a single color or shading pattern to show those states that have state sales taxes, state income taxes, and both sales and income taxes, leaving blank those states that have neither sales taxes nor income taxes.
Choropleth maps can be used to show differences in quantity also. If you wanted to show the percent of people graduating from high school on a world map, you could use ten colors to represent 0 to 10%, 11 to 20%, 21 to 30%, and so on.
Mapping information locates it for you. You know where it exists. And you have a starting point for finding out why it is there.
DIRECTIONS FOR CREATING A CHOROPLETH MAP
1. Determine the mapping categories.
3. Locate and label each country on an outline map, determine its mapping category, and color or shade the country appropriately.
4. Title the map and add the key or legend to the map.
Source: Population Data Sheet, Population Reference Bureau, Inc., April 1992.
From Geography: Focus on Economics, Lesson 7 © Council for Economic Education, New York, NY