Volume visualization - The Visualization of Spatial Social Structure - page 277

they will appear much darker than is usual, rather than as a single occurrence.
The three-dimensional electoral graphs would appear more like a cloud of dust
particles or a galaxy. The true density and sparsity of spatial divisions would be
apparent where, before, they had quickly obscured each other as a dark mass.
Lastly, there are the flows through time, depicting those so that it might be pos-
sible to trace the path of each migration stream through the myriad structure of
pipes and columns.
Translucence is not true three-dimensional imaging. To argue that is rather
like telling a two-dimensional being that can only see a one-dimensional strip
that, if objects were made translucent, it would see two-dimensional structures. It
would not. It would merely see what was previously completely hidden from its
view, and the viewer may, through rotating the angle and position from which it
viewed the two-dimensional space, come to guess some of its structure. However,
it would never have the full luxury of being able to see simultaneously all that
it contains and how it is arranged from above, because it is part of that two-
dimensional space. Similarly, in the real world, we will never have that visual
ability in three dimensions.

9.7 Interactive visualization

Just as 'visualization' has been invented to describe the process of
providing more immediate access to very large amounts of data,
'interactive visualization' will be 'invented' to describe the process
of providing more immediate access to the particular features that
are of interest to the analyst at particular points in both the spatial
and time domains of a given field.

(Dickinson, 1989, p. 10)

To bring the discussion up to date, in the late 1980s it was being claimed
increasingly that there were two types of visualization - the mundane variety,
which would include this topic, and the interactive kind, the most extreme
example of which is found in the artificial realities of computer graphics.
Interactive visualization, like interactive graphics, allows the viewers to
change instantly, but smoothly, the direction and position from which they are
viewing, what they are seeing and how it is depicted, lit, animated and so on.
What you see moves, and so can you.
Freedom to interact allows any aspect of a structure to be examined at
will. It is almost as if you could pick it up and turn it around in your hands.

'survey results', by which these authors mean aspects of social science. As yet almost no such '4D'
social science visualization has been achieved: 'Interactive computer graphics is the most important
means of producing pictures since the invention of photography and television; it has the added
advantage that, with the computer, we can make pictures not only of concrete, “real world” objects
but also of abstract, synthetic objects, such as mathematical surfaces in 4D ... and of data that have

no inherent geometry, such as survey results' (Foley et al ., 1990, p. 3).