Phenomena vs. Data
GIScientists distinguish between phenomena
"Phenomena are all the stuff out in the real
"Data capture a specific phenomena"
(Making Maps, p. 54)
Maps do not display
phenomena, they display data
Phenomena only exist in
the real world: "the map is not the territory"
This has implications,
1. We cannot collect
all data about phenomena, but only samples
2. Maps therefore are only samples of the real world
3. We choose which data are shown on maps. This choice is both explicit
(deliberate) and implicit
this temperature map the data are created from point samples of a surface
How Maps Work:
Associated Reading: Making Maps pp.
Visual variables can be used to appropriately symbolize your data.
Apply these to the spatial data models: point, line, area,
If your data are quantitative use size, color
If your data are qualitative use shape, color hue, orientation
Some variables can be used for both, such as texture, arrangement