Below’s a quick outline of the first maps created with six common cartographic symbologies. All of the below is out there, in books, articles, and blog posts. Particularly helpful are Alan MacEachren’s 1979 article The Evolution of Thematic Cartography, Arthur Robinson’s Early Thematic Mapping in the History of Cartography (1982), Borden Dent’s thematic cartography [...]
posts tagged 'choropleth'
Jun 01 2008
this is not a heat map
The term “heat map” has become increasingly confused. Perhaps it doesn’t matter, but for the record the above map is a choropleth map. It’s been branded by Google (as one of the Google Gadgets) with the sexier label “heat map”, and this (mis)usage is catching on. The term heat map is already [...]
Apr 08 2008
choropleth mapping and standardization
Choropleth maps, like the one above, use the visual variable of value (aka shade or lightness), sometimes in concert with hue or saturation, to present data about featues. Academic cartographers teach that this symbology should only be used in certain circumstances.
The phenomenon being mapped must be thought to vary only between enumeration units, and [...]