presented by: Tim Haithcoat University of Missouri Columbia with materials of: Dennis Fizsimons, SW Texas State University George McCleary, Jr., University of Kansas Designing Better Maps
presented by:
Tim HaithcoatUniversity of Missouri
Columbia
with materials of:Dennis Fizsimons, SW Texas State University
George McCleary, Jr., University of Kansas
DesigningBetter Maps
2
Design is a ChoiceDesign is a Choice
The theory of the visual display ofquantitative information consists ofprinciples that generate design optionsand that guide choices among options.
The principles should not be appliedrigidly or in a peevish spirit; they are notlogically or mathematically certain; and itis better to violate any principle than toplace graceless or inelegant marks onpaper.
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Design is a ChoiceDesign is a Choice
Most principles of design shouldbe greeted with some skepticism,for work authority can dominateour vision, and we may come tosee only through the lens of wordauthority rather than with our owneyes.
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Design is a ChoiceDesign is a Choice
What is to be sought in designs for thedisplay of information is the clearportrayal of complexity.
Not the complication of the simple, ratherthe task of the designer is to give visualaccess to the subtle and the difficult --that is, the revelation of the complex.
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GeneralizationGeneralizationSelection
Classification
Simplification
Exaggeration
Symbolization
Induction
ClassificationClassification
Unclassed Classed
SimplificationSimplification
less more
ExaggerationExaggeration
less more
SymbolizationSymbolization
Abstract Representational
InductionInduction
Positive Negative
.
. . .
.
. . .
after: Jacques Bertin. Graphics and Graphic Information Processing. New York: Walter de Gruyter, 1981.
Shape
Visual VariablesSp
atia
l Dim
ensi
on
Point0-D
Line1-D
Area2-D or
more
Direction
Textureor
Pattern
Coloror
Hue Size Value
R
G
Y
Y
Y
Y
R
G
GR
Qualitative Quantitative
Visual Variables TypographyVisual Variables Typography
Size
Value
Direction
Texture
Form
Color
Foreground
Background
Modified from: Borden Dent, Cartography - Thematic Map Design, 3rd ed. p. 264.
IncreasingVisual
Hierarchy
Scale/Scale/ResolutionResolution
200% 150% 100% 75% 50%
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Map Type & Symbolization Map Type & Symbolization (1 of 3)(1 of 3)
Symbol
Point
Point
Characteristics
flow of distribution & relative spatialdensity (high/medium/ low relativedensity)
“interval” construction - “ordinal” reading
Related & limiting variables used inconstruction
Specific point or areal unit -- actuallocation, centroid or weighted center
Good for:
– high/low values in close proximity
– Symbolizing totals
– Aggregate data for several locations orareas
Map Type
Dot Map
Graduated
Symbols
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Map Type & Symbolization Map Type & Symbolization (2 of 3)(2 of 3)
Symbol
Line
Line/
Surface
Volume
Characteristics
Width of line represents data along route
Segmented or uniform
Isometric - points/isoplethic - areas
Form of distribution & gradients mostimportant
Distribution treated as surface of a volume
Surface “contours” - ridges, troughs, peaks,etc. - arrangement or direction of magnitudes
Commensurable - data values can be derived
Planimetric - correct horizontal position(within accuracy limits of map)
For continuous data only
Map Type
Flow/
Network
Isarithmic
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Map Type & Symbolization Map Type & Symbolization (3 of 3)(3 of 3)
Symbol
Area
Area
Characteristics
Data by areal units - “enumeration units”
Relative location most important
Totals seldom mapped; usually derivedvalues or “averages” (mean, median, mode)
Ratios/densities - account for area
Ratios, percentages, proportions -eliminate area
For discontinuous data only (or datatreated as such)
Data by areal units
Continuous (connected) or discontinuous(separated)
Data scaled proportionately as unit’s area
Map Type
Choropleth
Cartogram
CommonCommonQuantitativeQuantitativeMap TypesMap Types
Choropleth Isoline
Dot Map GraduatedSymbol
Nominal
Ordinal
Interval
Ratio
Mea
sure
men
t Lev
elSpatial Dimension
Post Office
Church
Airport
Point0-Dimension
Line1-Dimension
Area2-Dimensions or more
City
Town
Village
1000
500
200
Population
10 - 15
5 - 9.9
.1 - 4.9
% Unemployed
Continental Divide
Railroad
Highway
Trail
Highway
Interstate
2 Lanes
4 Lanes
6 Lanes
1000
500
100
Vehicles (per hour)
BrownJonesSmithWilson
HighMediumLowVery Low
1945194719501954
>400200-40050-199<50
Persons perSquare mile
Ownership
Crop Yield
Date of Annexation
Population Density
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The Map Design Process:The Map Design Process:
PlanningPlanningWhat information do you need to convey?Is a map the best way to communicate thisinformation?What problem or question needs to be addressed?What information needs to be included?Is data readily available?Who is the audience?Is there a given style for this type of map?Will the map be part of a series?Sketch out several layout designsReality: money, materials, equipment, labor, & timeHow will I proceed?
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The Map Decision Triangle
Time
Quality
Cost
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The Map Design Process:The Map Design Process:
ComposingComposingWhat map elements need to be visually dominant?What will be the final size of the map?How will the map be reproduced?Does the title or caption clearly identify the mappurpose?Does each map element directly contribute to yourpurpose?Are sufficient base data present to support thespatial distribution?Do I need to define any map elements in a legend?Does the map communicate pattern(s)?Is the map too complex? Too Simple?
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The Map Design Process:The Map Design Process:
Editing & Proofreading Editing & Proofreading (1 of 2)(1 of 2)
Has the quality of the data been overstated?
Have sources of statistical or “borrowed” databeen cited?
Are there any typographic, grammar, or spellingerrors?
Are there any geographical errors?
Is the map legible and readable?
Has anything been omitted?
Have I communicated the information? How do Iknow?
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The Map Design Process:The Map Design Process:
Editing & Proofreading Editing & Proofreading (2 of 2)(2 of 2)
Does the visual hierarchy reflect levels ofimportance?
Do all of the map elements work as a whole?
Can anything be omitted?
Am I willing to let this map stand as a measureof my ability and accomplishment?
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Map Critique Checklist Map Critique Checklist (1 of 2)(1 of 2)
The overall look ofthe mapSubjective, oremotional, reactionsto the map(authoritativeness,pleasingness,…)Content of the mapPotential usesAppropriateness of amap for the purposeProjection
Accuracy, precisionGeneral mappingmethodPoint symbolsLine symbolsColor - aesthetics,suitability forrepresenting contentOther area symbolsType style, size,placementDetails
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Map Critique Checklist Map Critique Checklist (2 of 2)(2 of 2)
Suitability for theaudienceExecution & printingqualityLayoutScale of mapClarity of scaleindicators - literal &graphicLegend clarityTitle clarity &adequacy
Quality of the paperMap size, format,foldingContext of the map(series, individual;accompanied or notby text,…)Use of the map inpractice (e.g. roadmap/street map cannot be“tested” strictly in anarmchair)
Overall effectiveness
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Factors Affecting Factors Affecting Choropleth Choropleth MapsMaps
Data quality– Appropriate size, shape & number of
enumeration units– Scale of resolution– Availability -- alternatives (surrogate
variables)– Data preprocessing -- rate, ratio, or percentage
(derived values)
Number of classes– Classed or unclassed– 2,3,4,5,6,7,8,9 or n classes
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Factors AffectingFactors Affecting Choropleth Choropleth Maps Maps(continued)(continued)
Method of Classification– Subjective/natural breaks
– Optimization, standard deviation, equalintervals, quantiles, etc..
Legend Design– Actual values, rounded values, continuous
range values
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Factors AffectingFactors Affecting Choropleth Choropleth Maps Maps(continued)(continued)
Symbolization– Value shadings:
• Graded sequence - percentage (100% black - 0% white)
• Graded sequence (no 100% or 0%)
• Graded sequence which reflects actual data values(class means)
– Color/hue: natural versus arbitrary– Value shading of a hue or multiple hues
Texture of value shadings:– Resolution - fine to course– Dots versus lines