Short presentation on spatial data, what it is, how it works and some common errors. Presented at Irish Computer Society seminar on Data Quality, Dublin, September 13 2010.

1. GeoData – What's Special about Spatial? Richard Cantwell www.geographic.ie richard@geographic.ie twitter.com/GeoGraphicIE

2. Spatial data – data that is 'located in space'

3. Represent the curved earth on a flat screen or paper: Projections

4. Represent features: As points..

5. .. as lines..

6. .. as a series of areas.

7. Raster data.

8. inspire.jrc.ec.europa.eu INSPIRE Directive: Spatial Data Infrastructure Transposed into Irish Law July 2010 Fully implemented 2019 Covers: Data Metadata Network Services

9. John Snow's 'Cholera Map' from 1854 www.TheGhostMap.com

10. Mashup Crime data with current location (GPS enabled phone)

11. Unintentional errors Intentional errors Scale / projection issues Classification issues Selective Interpretation Generalisation Modifiable Areal Unit Problem (MAUP)

13. Trap Streets: The Map.. ..and the reality.

15. Port-au-Prince OpenStreetMap as of 11 th Jan 2010

16. Port-au-Prince OpenStreetMap 3 weeks later

17. www.geographic.ie