Geography Reference
In-Depth Information
The basic question for color design—and of course map design in general—is:
What is the aim of the map
-
maker
?
What aspect
(
s
)
shall be highlighted in compli-
ance with the aim
?
And what color choice is evoked by the character of the
phenomenon that is presented
? Options are:
1. The user task: The tasks users are to complete by means of a map are a crucial
decision criterion for map design. Andrienko and Andrienko (
2006
) give a
comprehensive overview of tasks for exploratory data analyses, such as:
a. In lookup tasks users are searching for an individual value in the map, such as
a sound pressure level of 65 dB(A), or looking up the value of an attribute in a
defined place. To complete these tasks it has to be ensured that colors can be
distinguished.
b. For pattern identification patterns in the data based on data-interpretation
according to the objective are highlighted:
i. Highlight a critical value, e.g., by means of a contrast-increase or a
hue-step. Resulting schemes are sometimes similar to diverging schemes
which makes the exceedance of a value striking (see section “Color
Contrast”).
ii. Induce a three-dimensional effect by highlighting, e.g., one end of the
scheme by means of color effects (see section “Color Contrast”).
2. The level of abstraction: This facet determines if the color scheme is consistent
with the natural color of the occurrence or an associated color, in line with the
characteristics of the sensory perception or if it is an abstract choice. We
distinguish:
a.
Realities and physical distributions and phenomena
: e.g., altitude levels, or
population density. Because these phenomena have some kind of visual
appearance the representation should be less abstract. Representations are
more intuitive if an association between their visual appearance and the
representation is facilitated. Therefore, e.g., high densities are usually
presented by means of darker color, giving the intuitive impression of
more
color meaning
more
subjects or objects per area.
b.
Phenomena that have a physical
,
but not visible presence
in space and are
measurable and perceivable, such as sound or air pollution. In this case the
association between the phenomenon and the representation is not based on
their visible appearance, but on other characteristics based on the user
s
sensory perception, e.g., annoyance for environmental noise. Consequences
for color design in such use cases have been described in section “Color:
Highly Associative and Emotional”.
c.
Data that do not have any physical presence
in space, e.g., inflation, national
debt, energy consumption, age of the population etc. The representation of
these examples is most abstract, they do not cause any sensory perception,
unless visualized. Hence the choice of a hue does not have to be intuitive, but
it will be helpful to consider certain color connotations.
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