Artificial reality - The Visualization of Spatial Social Structure - page 67

Cartograms are maps in which the particular distortion chosen is made
explicit. Area cartograms are drawn so that the areas representing places on the
paper or screen are in proportion to a specific aspect of those places. The aspect
most commonly chosen has been total human population; another age might
have chosen only adult men.
Population cartograms give another shape to the world. By choosing to draw
the surface of the earth as a population cartogram, we give everyone equal rep-
resentation in the image (Figures 3.5, 3.6 and 3.7). In the process we lose much
that is familiar, but then we do not learn through familiarity, and familiarity often
deters introspection.
Population cartograms far outnumber any other kind. They were first drawn
around a hundred and twenty years ago. In the 1960s algorithms were devel-
oped to construct them by machine, as their manual creation has always been
immensely tedious. Most used in the 1980s were generated manually, often very
artistically, although interesting mechanical means had also developed for their
production. Much effort went into this pioneering work, because much was hoped
of the media. What can be done today is largely a realization of what people
were trying to achieve in the past, what they argued over and how those disputes
were resolved. 9
The depiction of electoral geography is a frequent use of population car-
tograms. Here the population base is often the electorate, although it can be
political representatives when every area with one representative is given equal
size. On any traditional map of an urbanised country, the majority of political
constituencies are literally not visible to the naked eye (Figures 3.8 and 3.9).
The problem is particularly acute in countries such as Canada and Australia, but
still fundamental in all other regions of the world. The argument is not that the
conventional map distorts the message; it is that it cannot correctly convey even
a very small fraction of it.
Numerous insets, and insets within insets, or dynamic zooming (pushing apart
two fingers on the touch-screen) could be employed to try and see what is going
on, but they cannot form what is required - a single gestalt image, a unique
impression (Figure 3.10). By 2010 The British Broadcasting Corporation had
begun using cartograms in their election coverage. 10
9 'The Tobler algorithm is regarded as imaginative but highly inaccurate, slow due to the number
of iterations required by the algorithm, and guilty of producing an over generalized end product. ...
This led Nicholas Chrisman to write a competing algorithm which uses a different distorted plane
approach. In this scheme, each region or polygon has an amount of “force” applied to it based on
the variable's value being mapped (Dougenik et al ., 1983). The implementation of the Chrisman
algorithm ... currently exists as part of the mainframe GIS package ODYSSEY ... ' (Torguson,
1990, p. 20). Both of these algorithms have now been superseded by the Gastner - Newman algorithm.
See footnote 12 below in this chapter.
10 'Television companies might argue that these examples of animated cartography are too com-
plex for the average viewer to understand. But today's viewers are much more sophisticated than
their parents who were happy to watch a cardboard pendulum be pushed across the screen. It is
true that it will take some time to explain the graphics. But when have television viewers ever had
more time, than when they are waiting for the slow trickle of results to come in on election night'
(Dorling, 1994, p. 21).