This document discusses key principles of map design including selection of colors, symbols, labeling, and overall layout. It emphasizes that while there are scientific rules of map design, there is also an artistic element. The document outlines topics to be covered such as map scale and generalization, symbolization, choropleth mapping, use of color, and labeling. It provides guidelines for map elements like titles, legends, and orientation indicators. It also discusses classification schemes, issues with choropleth maps, effective use of color, and best practices for labeling and typography. Ethical practices of map design to avoid deception are highlighted.
2. There are some (scientific) rules in map design but much artistic judgement in terms of
◦selection of colours
◦symbology
◦labelling (format and position)
◦arrangement of overall layout
◦(plus data selection, projection, scale, etc)
Subtle changes in design (e.g. weight of a label font for particular objects) can yield big changes in how the map is read
Use (and mis-use) the power of design. ethical practices not to deliberately deceive
4. 1.Map layout
2.Map scale and generalisation
3.Symbolisation and graphic variables
4.Choropleth mapping & data classification
5.Colour
6.Labelling and typography
5. For presentation of maps, some conventions on what to include:
◦a title (or caption). clearly state what the map shows. plus relevant date of data, sources, missing values, author, contact info, etc
◦a legend, so any reader can interpret the content of the map. meaning of all symbol and colours
◦scale indication. translates distance on the map to distance on the ground
◦orientation indication (the good old north arrow)
◦borders and neatlines
8. what level of detail is shown
crucial to choose appropriate scale to work at
large scale map : small surface area in high detail (e.g. city plans)
small scale : large surface area in low detail (e.g. national road atlas)
scale represented as a statement (“one inch equals five miles”), a graphical scale bar, (useful for measuring lengths), or as a representative fraction (1:1250)
very few maps use scale consistently for every object
9. Key modes of generalisation
• distortion is inherent, inevitable, unavoidable
•may have to leave features off the map altogether
• avoid visual clutter, balance content and legibility
10. graphic language (of points, lines, polygon, icons and text) used to represent ‘real’ features on the map
legibility (‘practical’)
harmonious (‘pretty’)
symbols can be iconic, geometric or abstract
symbol selection is creative aspect of design, wide choice and few firm rules
symbols can have several different dimensions (properties or characteristics) which encode meaning
symbols can have quantitative or qualitative meaning
13. choro from choros (place) and pleth (value)
counterpart of histogram
aggregate data, usually ratio or percentage
data map for discrete spatial units
practical Issues
◦choice of intervals - number and their breaks
◦equal interval, equal share (quantiles), standard deviational, …
choice of colors
◦important for perception of patterns
misleading role of area of spatial units
◦larger areas “seem” more important
14. classification is a key method of abstracting reality into simplified map
method of classification is important as effects ‘look’ of the map
classification scheme can easily be experimented with (manipulated?) to give the pattern you want
classification should ‘match’ data distribution
number of classes. can reader interpret between them? recommended max of 6
distribution of zones into classes
15. Same data plus different classification equal different looking choropleth map!
20. colour is one of most exciting aspects of design
colour perception is a combination of physiological (sensing in the eye and cognitive processing) and psychological reactions
colour evoke emotions. subjective reaction to colour
connotative meanings of colour. See Dent (1999, page 295)
21. cultural specific. also colour blindness. 7% of men and 1% of women
warm colours (red, orange, yellows)
cool colours (violet, blue, greens
defining - hue, saturation, value (HSV) model
22. hue - basic colour we perceive, eg 12 step Wheel saturation - intensity or purity compared to a neutral gray value - lightness or darkness. Can be hard to perceive variations in value
23.
24. gives structure and readability
developing figure and ground relationships
◦warm colour better for figures. Said to ‘advance’ to viewer. Cool colours tend to recede
perceptual grouping of like features through colour
colour contrasts. using value or saturation to represent data on thematic maps
qualitative conventions - blue for water, green for lush vegetation; red = warm and blue = cool in temperatures; hill shading
25. lettering choice can have a significant impact to effectiveness of the map
map text to label features has several key parameters
◦font typeface, size spacing
◦placement and orientation
importance of type discernibility
map labels can communicate important data, e.g. hierarchy of features, implying importance
Chislehurst, Bromley, L O N D O N
manual labelling of features can get very tedious. but automatic label placement is still far from perfect
26. Think about different types of lettering styles and placement/orientations used and the effects it has
27. ◦legibility of individual letters is of paramount importance, especially in smaller type sizes. Choose a typeface in where there is little chance of confusion between c and e and i and j
◦select a typeface with a relatively large base height
◦avoid extremely bold forms
◦choose a typeface that has softer shading; extreme vertical shading is more difficult to read than rounder forms
◦do not use decorative typefaces on the map as they are difficult to read
28. 1. always have a straightforward agenda, and have a defining purpose or goal for each map
2. always strive to know your audience, the potential/likely map users
3. do not intentionally lie with data
4. always show relevant data whenever possible
5. data should not be discarded simply because they are contrary to the position held by the cartographer
6. at a given scale, strive for an accurate portrayal of the data
29. 7. the cartographer should avoid plagiarizing; report all data sources
8. symbolization should not be selected to bias the interpretation of the map
9. the mapped result should be able to be repeated by other cartographers
10. attention should be given to differing cultural values and principles
30. ◦Borden Dent, (1995) Cartography: Thematic Map Design, fifth edition
◦Terry Slocum, (1999) Thematic Cartography and Visualization
◦Menno-Jan Kraak and Ferjan Ormeling, (1996) Cartography: Visualization of Spatial Data