cartogram

cartogram (plural cartograms)

1. (dated) A map used to indicate geographically-bound statistical information, typically region-by-region values of a given variable, for example by using different shadings for different ranges of values.
   • 1888 October, Dewey, Davis R., "Elementary Notes on Graphic Statistics", in the Massachusetts Institute of Technology Technology Quarterly, Volume II Number 1, published by the students (1888–1889), p. 99,

     […] whether, however, two states with these respective ratios do not consequently sufficiently differ […] as to warrant distinction in the cartogram, is open to question.

   • 1895, "Book Notes", in Academy of Political Science (U.S.) and Columbia University Faculty of Political Science, Political Science Quarterly, Volume X Number 3, Academy of Political Science (1895), p. 560,

     The fifth cartogram illustrates the criminal statistics for the period 1882-91, which are of unusual interest because […]

   1. A map-like graph where the relative areas of graph regions are proportional not to the relative areas of the land regions they represent, but rather to another quantitative variable, such as population or gross domestic product.

• A map-like chart: area cartogram, isodemographic map (when the variable used is population), value-by-area map

• Gillard, Quentin. "Places in the News: The Use of Cartograms in Introductory Geography Courses." Journal of Geography. 78 (1979): 114-115.