Choices in How We Make Representations - A Primer of GIS: Fundamental Geographic and Cartographic Concepts - page 46

or intend to use them for. By “quality,” we usually mean “reliability,” but
quality often simply means that a map fits the intended use. For example,
you could use highway maps to figure out the average size of towns in a state,
but the results would be of low quality. The concept “fitness-for-use” helps
people working with maps and geographic information to get a grip on the
slippery concept of quality. What this means is that we need to know the
intended purposes of a map before we can decide what level of quality the
map has.
At this point, it's important to recognize that the choices made for geo-
graphic and cartographic representation affect quality. The example of the
differences between projections and coordinate systems is merely the tip of
an iceberg that following chapters will develop in much greater detail. Going
back to the river flooding example and thinking about the choices between
vector and raster representations, you may grasp the significant conse-
quences of this choice for cartographic representation and the accurate com-
munication of flood events and how this is important for any and all geo-
graphic information and maps.
Summary
The representation of things and events from the world involves choices,
which are greatly inf luenced by conventions. The choices are endless, mak-
ing conventions critical to successful communication. Representation of
things and events distinguishes between geographic representation and car-
tographic representation. Geographic representation is the abstraction of
measurements and observations to geographic information. Sinton's frame-
work provides a useful tool for considering different ways that things and
events are geographically represented as information in terms of time, space,
and characteristics (attributes). The relationships among things and events
in a geographical representation are critical for cartographic representa-
tions. Cartographic representation creates maps and other visual representa-
tions and takes myriad cartographic presentation issues into consideration
including scale, symbols, and graphic variables. Successful communication
can be considered in terms of quality, especially the “fitness-for-use” of the
geographic information or map.
In-Depth The Parts of Maps
If some people had their way, every map would always include five elements
that aid in understanding by whom, why, and when a map was made. However,
like all recommendations these five parts are suggestions, not requirements.
The five essential elements of maps are:
Legend (special note re color)
Scale
Orientation