DATA OUTPUT

1. DATA OUTPUT maps tables

2. DATA OUTPUT • output from GIS does not have to be a map • many GIS are designed with poor map output capabilities • types of output: • text - tables, lists number or text in response to query • graphic - maps, screen displays, graphs, perspective plots • digital data - on disk, tape or transmitted across a network • others (not common) - computer generated sound, 3D images

3. DATA OUTPUT Presenting Maps and Data • audience and information content • knowing your audience • knowing what information to present • showing data to the general public should be simple and easy to read • know your data • how many maps do you need? • how much detail do you need? • how many themes do you need? • how many features do you need?

4. DATA OUTPUT • concise title • topic, place, time • “Unemployment Percentages, Pittsburgh, PA 1990” • scale • direction indicator • north arrow - only for unusual orientations on large-scale maps • use geographic grid on small-scale maps • base map • information for visual locational reference

5. Bad Map DATA OUTPUT

6. VISUALIZATION TECHNIQUES • measurement scales • must facilitate interpretation of spatial objects and attributes • classification • how do we measure/organize things? • spatial: points, lines, areas, surfaces • measurement: ordinal, interval, ratio • are often subjective

8. ATTRIBUTE REPRESENTATION Graphic symbols • features shown on map can be differentiated and identified in various ways: • symbols • colors • sizes • labels (greatest flexibility) • considerations: • legibility, hierarchy, overlapping, balance

9. DATA OUTPUT • is appearance really important in a map drawn to support decision-making? • GIS output maps are to be used directly, not destined for walls or map libraries • should GIS products be simple, schematic, avoid high cost of manual cartographic quality? - NO

10. DATA OUTPUT Screen Display • issues are different because screen is: • smaller, lower resolution than a printed map • more flexible • principles of design of screen displays are poorly developed • black or white background? (color perception) • system is interactive, can display limited information but access to more • eg. user clicks on or points to an object

11. DATA OUTPUT Text Output • perhaps more important than maps for reporting results of analysis • results might be a list or table of selected objectives with attributes • queries might result in numerical results (totals, distances, areas, counts) • text output might be delivered by a voice generator (navigation instructions - “turn left at next traffic signal”

12. DATA OUTPUT Reports on Layout • select records to include • generate a report • add report to the layout

13. DATA OUTPUT Graphics on Layout • select records to include • create a graph and include on layout

14. DATA OUTPUT 3-D display • some vendors are now offering 3-D stereo display devices • create the illusion of depth of rapidly switching between two images (left eye and right eye) • user wears eyeglasses containing clear polarizing filters • display must operate at 50-100 images/second

15. GEOGRAPHIC INFO SYSTEMS

16. No Class on Wednesday Review on Friday Final Test on Monday and Wednesday @ 2:30 – 4:30