Univariate Choropleth Map

This map was taken from http://www.cdc.gov/pcd/issues/2007/oct/07_0091.htm

This is a good example of a Univariate Choropleth Map.  This is a univariate map because there is only one factor that is being taken into consideration.  In this case it is the percentage of individuals living in poverty by county.  There are no other variables that are involved in making this map.