Nominal area choropleth map

Nominal area choropleth maps are choropleths maps that visualize nominal data such as percentages and ordinal numbers over a particular spacial area.

http://my.ilstu.edu/~jrcarter/Geo204/Choro/Tom/

Standardized Choropleth Maps

Standardized Choropleth maps use the ordinal progression of various classes from a spectrum of high to low and etc. In these maps the variable measured is standardized to help provide the information in an easier way to understand.

http://www.cdc.gov/pcd/issues/2007/oct/07_0091.htm

Unstandardized choropleth maps

Unstandardized choropleth maps do not have ordered classes. The various map variables are not ranked against one another hiearchally.

http://pubs.usgs.gov/fs/2005/3051/

Univariate choropleth map

A univariate choropleth map uses one determinate variable which is visually represented through a single shading choropleth scheme; ultimately reflecting frequency of that particular variable.

 

http://www.geog.le.ac.uk/russianheartland/DemographicMaps/Raions.html

Bivariate chororpleth maps

A Bivariate choropleth map uses two determining variables each with its own choropleth color gradant scheme. The overlapping of these colors sometimes makes it difficult to read the data.

http://www.directionsmag.com/images/articles/sportsillustrated/Olympic_Athletes.jpg

Unclassed Choropleth maps

In objection to classified choropleth maps, unclassed choropleth maps utilize a continuum shading technique to represent frequency that is not affective cartographic decision. The picture above is comparing the two different types of unclassified and classified representing the proportion of married couples.

http://gis.depaul.edu/shwang/teaching/geo381/LN9.htm

Classed Choropleth Maps

A classed Choropleth Map is when you divide data results into equal interval or frequency categories. This was used in the past to help represent different data values with minimal colors on printed maps.

http://krygier.owu.edu/krygier_html/geog_222/geog_222_lo/geog_222_lo11.html