Quality of maps Flashcards
Learning how to asses the quality of maps through criteria
Name all (7) Bertin Visual variables?
- Size 2. Shape 3. Color Hue 4. Color Value 5. Color Saturation 6. Orientation 7. Texture
Name 3 color schemes and their type of variable
Nominal color scheme (nominal) Sequential color scheme (Ordinal) Diverging color scheme (Interval)
Whats wrong with New Cuyama?
Wrong addition of different mesurment scales!
Characteristic measurement scales
- Interpretations of signs into a domain of measurement - For example, interpretation of “1” into a length (meter) - Fixed by convention (think about the prototype meter)
Level of measurement
(1)Popular thematic map types:
What kind of map is it and how does it work?
A choropleth map is a thematic map where geographic regions are colored, shaded, or patterned in relation to an attribute value
(2)Popular map types
Proportional symbol map
A symbol is used to represent data at specific or aggregated point.
(3)Popular map types
What does this map show?
Dot density map:
Uses a dot to represent a feature or attribute in your data
Example John Snows Cholera map
(4)Popular map types:
Contour map show intensities in terms of contours
Example: drought severity us
Attribute normalization and map type:
Extensive vs intensive attributes
How is this map made and what is wrong about it?
Choropleth map was produced by summing up camels without normalization
Remember: Never use non-normalized (extensive) attributes with choropleth maps
Attribute normalization and map type:
Extensive vs intensive attributes
What map type is better for visualization?
Better use porportional symbol maps for extensive attributes!
Using Bertin variable: Size
What are the criteria to consider according to Slocum? (7)
- General or specific
- Spatial dimensionality and map scale
- Level of measurment
- normalization (extensive/intensive)
- many attributes (multivariate mapping)
- role of time (temporal mapping)
- Cartograpic design prinicples
