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The arrows worked well in this example because direction was meaningful;
left and right as shown here are political terms, not compass directions. They
also work well because the spatial relationships in voting were strong enough
for discernible patterns to exist. 8 If the purpose had been to look at the effect
of changing employment, migration, housing and industrial influences upon the
elections visually, these simple arrows would not have been so useful.
8.5
Trees and castles
... until Britain moves decisively towards a more-equal society again,
its inequalities will continue to express themselves as a north-south
divide.
(Lewis and Townsend, 1989, p. 19)
More complex glyphs than arrows have been specifically designed to allow
a quick comparison of the overall pattern of multivariate information. The
most accepted of these usually take the form of trees or castles, where various
aspects of a basic shape are altered to produce many variations of an underlying
structure that aids their comparison. It is the maintenance of this basic structure
that easily assimilates into a picture that distinguishes these glyphs from the
polygons, bars and pyramids described earlier. They have specifically been
designed to be glyphs.
Castles have various parapets, which alter in height and aspect as the values
of the variables change. In many ways they are simply an embellishment of the
bar chart, altered so as to allow the mind to form an impression of the general
shape of the place more easily, using a more familiar symbol. Bar charts can only
go up or down; they can have a peak here or there, but they are still showing a
pattern within the chart. Castles appear more as single objects, and so it is hoped
that an overall image can be obtained.
Instead of castles a more familiar alternative of houses could be employed,
where the shape of the roof, size of the windows and so on would be altered to
show information. Thus a town of houses would be created, allowing particular
suburbs, estates and streets to be identified. This method might be especially
appropriate if it was aspects of housing amenity at different places that were
of interest. 9
House prices for broad categories of housing are shown through
8 The geographical pattern to changes in political swings is not simple: 'Using entropy-
maximising estimates of the flow-of-the-vote matrix for each constituency in the 1979 - 1983 and
1983 - 1987 inter-electoral periods, this paper
...
indicates clear geographical variations that are more
complex than the simple north - south and urban - rural dichotomies often applied' (Johnston and
Pattie, 1988, abstract, p. 179).
9 It is interesting that places with extreme (high and low) house prices also share the extreme
positions in analysing their census data: 'There were six clusters with fewer than five districts
including two in which single districts are so distinctive that they each form a cluster on their own.
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