Choosing Symbols
Reading in Slocum: Chapter 4
Phenomena:
•
point,
line, area, volume
•
discrete
––> continuous
•
smooth
––> stepped (abrupt)
Levels of measurement:
•
nominal
•
ordinal,
interval, ratio
Visual variables:
• for
qualitative differences (nominal, categories):
hue, shape, arrangement, orientation
• for
ordering (hierarchy; ordinal, numerical):
lightness, size, spacing, saturation, height
Spatial dimension:
•
symbols
emphasizing points, lines, area, 2½D, 3D
see Fig. 4.3 and Color
Plate 4.2
What are
characteristics of example maps?
Area examples: choropleth, proportional symbols, isopleth, dot map
Ordered:
