Envisioning information - The Visualization of Spatial Social Structure - page 20

things must change smoothly and relatively slowly. 15 If objects change their
colour it can confuse; if too much is happening we will not have enough time to
comprehend it.
Surprisingly, animation takes us back towards illustration. It requires simplic-
ity to work. Far more useful are interactive graphics - moving pictures that the
viewer controls. An App on a mobile phone is an easy contemporary example
of an interactive graphic. The viewer has control. This is not only control over
how fast or slow or where the pictures move, but simultaneously over what they
contain and how they are presented. This interactivity is a possible next step
in visualization that may allow more of the types of image shown here to be
created, understood, manipulated and used.

1.6 Pattern and illusion

... the differences between maps and other forms of graphic informa-
tion are not as great as they appear. All types of graphic information
are different solutions to a common problem: our limited capacity
to remember unprocessed information. By removing the limitations
of short term memory, graphic information allows us to do kinds of
thinking which are difficult or impossible in other ways.
(Phillips, 1989, p. 25)

We do not think in a three-dimensional geometry - many tests have shown
this, although a variation in propensity for such thinking may exist between men
and women. 16 The geometry of visual thinking is essentially two-dimensional.
We also have a poor visual memory; we remember what we extract from images
rather than the images themselves. Furthermore, the emotional overtones of
colour are perceived differently by different people.
The colour blind cannot see the full trivariate range. Advocating trivariate
mapping went against many of the embryonic tenets of visualization, but it is
questionable how much they were guided by what was possible, rather than
what was desirable. Why use the illusion of three dimensions if it adds so little
information to an image while causing so much confusion? Perspective views

15 In a visualization, involving animation is often best if objects don't move very much: 'Several
trial films revealed one very necessary characteristic of animated mapping: simplicity and extreme
clarity are essential. In a static map, the reader has time to interpret complex or unclear information.
However, this is not the case in animated mapping where the image must be interpreted immediately'
(Mounsey, 1982, p. 130).
16 The kind of test that uncovers our general inability to think in 3D geometry is to try to imagine
the shape made by a hot cube pressed, point down, into a think sheet of ice (Parslow, 1987). The
answer is an equilateral triangle (if the cube is held steady). Many people say 'square'. Men are,
apparently, on average a little better at such imagining than women. It is one of the very few tests
where men do perform better. Researchers speculate that it helps in throwing spears better, but also
that throwing spears may have been more important for impressing women than for catching meat.