scale, Compilation, and generalization 79
The decision regarding how much base data and what type to use depends on the
purpose of the map, the location of the subject area, the scale of the map, and the pre-
sumed audience. This selection process is a part of generalization, which is discussed
later in this chapter. For example, a map showing climates of the United States would
not normally call for transportation routes, unless the objective is to show a relation-
ship between these features. In that case, the transportation net would become a part
of the thematic information. The outline of the states and the location of major cities
would be desirable for reference.
A frequent problem involves the amount of surrounding
area that should be
shown. Should only the outline of the area in question be drawn, or should the map
extend beyond the borders of the subject area and include
the neighboring areas
(Figure 5.5)? Children sometimes assume a country ends where the map ends. Even
adults, when confronted with an unfamiliar area, may need more background infor-
mation to orient themselves. A very general rule of thumb is that, for a familiar area,
such as one of the individual states of the United States (for American audiences), it is
acceptable to show only the outline, but for an area assumed to be less familiar to the
reader, such as Uruguay, Botswana, or the Czech Republic, some surrounding areas
should be included as base information. Another way of handling this problem is to
include an inset map that shows the surrounding area.
sOURCes OF inTeRnaL Base DaTa
Often base data are taken from other maps, but locating appropriate base and refer-
ence maps can sometimes be difficult. If one is employed by a mapmaking agency,
one can utilize the in-house map collection, but if one is an independent cartographer,
one needs to utilize other sources. Obvious sources are sheet maps or atlases from
government agencies, private companies, and institutions. One should also become
familiar with local map sources such as university libraries and public libraries that
have map collections. If such source maps are used in compilation, one must be aware
of the copyright laws governing the use of published works. If a suitable base map is
URUGUAY
URUGUAY
