Chapter 5. Presenting Data

Transcription

1 Chapter 5. Presenting Data Copyright McGraw-Hill Education. Permission required for reproduction or display. 5-1 Basic principles of map design 5-2 1

2 Map Design Process 5-3 The map objective The first important design step Four key questions to answer What is the purpose? Who is the audience? What is the medium? Under what conditions will it be viewed? 5-4 2

3 Maps serve many purposes Locating Navigating Compiling Convincing Comparing Analyzing.? angepairs/index.html _sheet1.pdf s/highways_k12.jpg Audience Who will be viewing the map? What is their expected level of knowledge? About the subject matter About maps in general Do they have special requirements? Black and white? Color blindness, large print? 5-6 3

4 Medium Paper map Report? Wall map? Poster? Electronic files (pdf, gif, etc.) What format(s)? File sizes? Delivery method? Computer screen What size? Which types of computers? Projection screen Mobile devices/tablets/smartphones 5-7 Design for the medium Paper maps Static and unchanging Fixed paper size and scale High resolution May be complex with many levels of information Viewer is committed May serve multiple purposes Web maps Interactive Viewing size may vary by device screen Poor light/sunlight on mobile devices Short viewer attention span Competes for attention Should do one thing really well 5-8 4

5 Select 5-9 Selecting the data layers A good map tells a story Who are the lead players? Which layers play a supporting role? Do some layers distract from the story? Or obscure it?

6 Should you omit some data? Privacy issues Publishing parcel owner names Sensitive information Fossil or archeological sites (poaching issues) Endangered species locations Pipelines or climate stations (vandalism concerns) Unintended economic consequences Showing faults that intersect parcels Publishing water tests of private wells 5-11 Selecting within layers Sometimes need to simplify a data set for better performance on a map Known as cartographic generalization Adapt large-scale data to a smaller scale map

7 Using a query Show a subset of features Quakes > 4.0 Quakes > Cartographic generalization Refine Reclassify Simplify Typify Aggregate Displace Collapse Exaggerate

8 Selecting a map projection From Wikipedia: a map projection is a systematic transformation of the latitudes and longitudes of locations on the surface of a sphere (or an ellipsoid) into locations on a plane (a flat surface). Map projections are necessary for creating maps. More info: Selecting a map projection

9 Selecting a projection A map using a Geographic Coordinate system (GCS) (i.e. WGS 84) appears distorted. Always use a projected coordinate system for mapping Distortion All map projections distort the surface in some fashion. The four spatial properties subject to distortion in a projection are: Shape Area Distance Direction

10 Distortion

11 Distortion Unintended consequences Projection choice may affect the story Mercator maps make northern hemisphere look more important

12 Types of projections Cylindrical preserves shape and direction Conic preserves distance or area Azimuthal usually preserves distance 5-24 or area Universal Transverse Mercator (UTM)

13 State Plane 5-27 Graticule grids A north arrow is not appropriate for some projections because they distort direction. You should place graticule grids on the map instead.? Maps that distort distance should not have scale bars

14 Other types of map grids Measured grid (UTM meters) Reference grid 5-29 Arrange

15 Visual hierarchy The order in which a reader perceives the different objects in a design A good map establishes a clear pathway that highlights the important aspects Look at the map on the next slide for a few moments

16 Visual hierarchy What was the map about? What did you notice first? How did your eye move around the map? How was the path achieved? 5-33 Establishing a visual hierarchy Visual center Rule of thirds Balance Alignment Negative space Neatlines Symbolization Color Contrast Size/thickness Foreground/background

17 Visual center is higher than the geometric center Visual center 5-35 Composition rule for photographs Place important items at intersections Rule of thirds

18 Alignment Use columns Align edges 5-37 Balance it evenly Don t crowd elements Don t leave big empty spaces Use as another design element Subtle way to group things Negative space

19 Balancing elements 5-39 Symbolize

20 Symbolizing for hierarchy What stands out? How is it achieved? Color Contrast Foreground/background Size/thickness Symbol/font Spacing/grouping 5-41 Symbols and patterns The brain doesn t just observe, it tries to find patterns How do you make things stand out? Belong together? Show difference in quantity? Difference in category?

21 Which map has a clear visual hierarchy? How is it achieved? 5-43 Base maps How does this base map establish visual hierarchy?

22 Review and edit 5-45 Reviewing the draft Check balance Visual hierarchy Print to check colors, if a paper map Spelling, grammar, details Are all required map elements present? Scale bar / north arrow / legend Did you remember your sources?

23 Pay attention to details! Crowded Unclear name Abbreviations Poor formatting Much better!!! 5-47 Review this map

24 5-49 Other Examples

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27 External review Very helpful to have others review your map People similar to the intended audience People in your field Graphic designer (if you can find one) 5-55 Edit and improve Concentrate the message Simplify, simplify Experiment Test under conditions of use

28 You re done! (maybe )