Taxonomy of Data Visualization Methods - Data Visualization: A Successful Design Process - page 149

Image from "Perpetual Ocean" ( http://www.nasa.gov/topics/earth/features/perpetual-ocean.
html ), created by NASA/Goddard Space Flight Center Scientific Visualization Studio
Cartogram
Data variables : 2 x quantitative-interval, 1 x quantitative-ratio.
Visual variables : Position, size.
Description : Where a choropleth map takes a location and gives it a shade of color
to represent a value, a cartogram takes a location and resizes the geographic shape
to represent a value. The result is a distorted and skewed view of reality in the form
of a reconfigured atlas. As with many of the chart types outlined here, the purpose
is not to enable exact readings, rather to highlight the highly inflated, deflated, and
unchanged shapes and sizes. They do rely on a certain predeveloped familiarity
of (for example) a country's position, its shape, and its size. The most effective
deployment of such charts tends to be when they are interactive and you can
unlock all the benefits of exploratory analysis. An example is given here:
Image from "All Cancer Deaths: 2002" via Worldmapper ( http://www.worldmapper.org/images/ )
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