Saturday, August 1, 2009
This bivariate Choropleth map was found at: http://2.bp.blogspot.com/_mNAOq8ApgBA/SViWmdk-5aI/AAAAAAAAAgY/0fEHL3zyvsk/s400/Income+Distribution+By+Race.gif Bivariate choropleth maps show data for two variables. For example, this could be the population by race, or gender in the U.S.
This Unvariate Choropleth map was found at: http://www.mint.com/blog/wp-content/uploads/2009/04/mint-income-r3.png
Unvirate choropleth maps are useful in showing data for a single variable. This could be the percentage of population that are getting the swine flu, or that make more than $50K per year. It would not show multiple variables data.