Nominal Area Choropleth Map

A nominal area choropleth map displays data, which cannot be measured or calculated. The data is grouped, labeled, and randomized. The groupings are represented by color or patterns

The example map is of an example nominal area map, from the explanations on cartographic symbolization and design within ARC/INFO Methods

Reference URL: http://amlcartography.sourceforge.net/chapter5/c5_2.html