Standardized Choropleth Map

http://upload.wikimedia.org/wikipedia/commons/thumb/7/78/USA_states_population_density_map.PNG/800px-USA_states_population_density_map.PNG

A standardized choropleth map is a choropleth map which has been areally averaged, or averaged to some unit (e.g. "per square mile", or "per acre"). This choropleth has been areally averaged to population per square mile by state, so it is therefore standardized.