Answers are grounded in this paper and cite their sources.
In recent years the U.S. Bureau of the Census has produced a number of thematic maps in color. These maps, appearing in various publication series, utilize predominantly the choropleth method. A variation in the use of this method is the two-variable "cross" map on which the distributions are mixed to represent category combinations. An important technological development that has enabled the production of color maps, specifically those in the Urban A1lases, has been the use of computer output on microfilm.
No takes yet. Share an insight, caveat, or question.
Meyer et al. (1975) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: