The Dimensions of GIScience

1. The Dimensions of GIScience Jonathan Raper http://www.soi.city.ac.uk/~raper raper@soi.city.ac.uk

2. The achievements of GIScience • Efficient geometric models in 2D, 2.5D, 3D • Management of massive distributed datasets • Satisfaction of deterministic spatial queries • Multi-scale spatial analysis • Development of geo-visualization techniques • Geolibrary foundations

3. The challenges Can we say that these achievements give us an adequate account of geographic information in theoretical or application terms? What are the dimensions of GIScience that we don’t have a grip on yet? That’s the subject of this talk…

4. 1 The tyranny of map features • Problem: we ignore what is outside the ‘topographic consensus’ • One solution: explore the dimensions of geo-ontology

5. image courtesy of Simultec AG, Zurich, Switzerland. 2 The fetish of the static • Problem: we cannot represent what we cannot frame • One solution: explore new representations of the dimensions of space and time

6. 3 The slavery of the panoptic • Problem: we neglect the individual perspective in favour of the ‘map’ overview • One solution: explore the dimensions of perspective in system interfaces

7. 4 The dangers of the irrelevant • Problem: we assume systems deliver cognitive adequacy • One solution: explore the dimensions of relevance

8. 5 The fallacy of the impersonal • Problem: we violate privacy through generalisations over space and time • One solution: explore the dimensions of privacy

9. 1 The tyranny of map features • Where do the features on maps come from? • What are the actual user concepts/language of geo-phenomena? • How should these concepts be captured and represented?

10. The topographic consensus • The (locally-adapted) standard set of ‘features’ appearing on topographic maps • How much of a consensus is it really? • The catalogue is a function of • History • Interest groups • Agency responsibilities • Study of this by Smith (1979)

11. Data exchange standards ‘Part 2 of the SDTS is the first formal attempt to develop a standardized list of entities. Should be viewed as not "just another list of features and attributes" but again, as a standardized list of features and attributes.’ ftp://sdts.er.usgs.gov/pub/sdts/articles/ DLG-E does a better job, but…

12. Mappable geometric promitives • Our current geometric models are topologically complete and fully-specified • See Worboys (1995) • What about ‘supra-topological’ concepts like: • Shadows • Easements • Bays

13. Geo-ontology • The identity of geo-phenomena can be defined as: • spatio-temporally constituted difference… • driven by feedback between the causal and the contingent and … • highlighted by human intentionality • ‘The act of projection from the world of four dimensions to a geographic plane is to make it impossible to fit many entities into a geographic ontology’ Raper (2000)

14. Geo-ontology example • An ontological survey of coastal geo-phenomena with Ian Densham (http://vlib.city.ac.uk/) • Concordance of user terms • Aggregation into surrogates • Classify surrogates as geographic kinds • Natural (e.g. river) • Cognitive (e.g. neighbourhood) • Geopolitical (e.g. state boundary) • Compare with map features • Characterise their temporal behaviour

15. Geo-ontology vs map features

16. Compare geo-ontology with maps

17. Temporal volatility

18. 2 The fetish of the static • Our main representations: 2D, 2.5D • Snapshots, time as an attribute • Discrete change • Spatial coherence > temporal coherence • e.g. geo-phenomena like ‘hurricane occurrence’? • We should explore spatio-temporality • Spatio-temporal geo-phenomena • e.g. tidal flows, congestion • Need a wider range of space-time structures

19. Space-time typology Discrete (spatial metrics) Absolute (identity=location) Integrated (true spatio-temporality) Hybrid (space & time different) Relative (Identity=character) Continuous (math function) From Raper (2000)

20. Space-time structures

21. Representations for time • How to represent the spatio-temporal? • Problem becomes how to ‘entify’- i.e. find phenomena extending across space, through time • Points: the ultimate spatio-temporal primitives? • Bridge between the continuous and the discrete • Allows the conjectural assembly of phenomena

22. Space and time examples • 1 A study of individual urban spatio-temporal mobility structures with David Mountain (http://www.soi.city.ac.uk/~dmm/) • 2 A study of the evolution of moving natural objects with David Livingstone (http://www.kingston.ac.uk/)

23. Personal movement histories • Individuals carrying positioning devices • GPS (we have carried them for >1 year to collect real data) • Location-enabled phone • On an individual basis • Can explore individual ‘territory’ • Can attempt to guess what they are doing • On an aggregate basis • Can study ‘emergent’ spatio-temporal phenomena such as congestion • Spatial History Explorer for Webpark project (http://www.webparkservices.info/)

24. Jonathan’s spatio-temporal movement for the whole of summer 2000 in SHE Green is weekdays

25. Jonathan’s week in 2D 1km Each colour= 1 day Darker= later in the day

26. Jonathan’s month in 3D X & y axes are spatial and z is seconds from midnight. Points are from GPS carried on all journeys with static time auto-completed. Model produced by Earthvision (http://www.dgi.com/)

27. My 3D space-time Model as last slide but with 3D isosurfaces interpolated on speed and only >35kph shown

28. Landform movement histories • Scolt Head Island, Far Point sand spits in 1997

29. Spatio-temporal change Contour maps from 1992-9 for Far Point, Scolt Head Island. Contours are 1m interval, map is approx 1km across. Details in Raper (2000)

30. Spatio-temporal behaviour 3D model of all 17000 elevation points collected at Far Point, Scolt Head Island 1992-99 shaded by sediment code (fine= purple, coarse= yellow, sand dunes= red)

31. Spatio-temporal identity • How to represent stability and movement? • How to spatio-temporally interpolate? • Use absolute space for referencing and relative space for identity?

32. 3 The slavery of the panoptic • GIS offers us overview… users have point-of-view • Psychological distinction between the allocentric and the egocentric • Panoptic=detached • Individual=immersed • Need egocentric representation and interfaces

33. Perspective examples • Location-based services information delivery • Push (alerts e.g. danger warning) • Deterministic (queries e.g. what is here) • Probabilistic (task-related e.g. how well am I doing? • Egocentric task applications with geographic knowledge needed

34. Profile application for PDA Webpark project prototype

35. Egocentric applications • Usability is key • Don’t overload the interface • Real users don’t ‘understand’ why it doesn’t work • Kids are the best testers!

36. 4 The dangers of the irrelevant • What is cognitive adequacy in geographic information? • Depends on geographic information needs • Requires a concept of geographic relevance • Personalisation

37. Geographic relevance From Raper (in press)

38. Relevance example Egocentric information needs- demand a locationally and task relevant response

39. 5 The fallacy of the impersonal • The dimensions of privacy in an information society • Public persona • Private persona • Public persona can be characterised from aggregate data • ‘ecological fallacy’ • Private persona can only be acquired from individuals • Need to make a case e.g. to track movement

40. To conclude • The tyranny of map features • Overthrow it! • The fetish of the static • Admit you need help! • The slavery of the panoptic • Emancipate yourself! • The dangers of the irrelevant • Up your profile! • The fallacy of the impersonal • Engage with people!

41. References • Smith, W. (1979) National mapping: a case for government responsibility. Conference of Commonwealth Surveyors 1979, Paper M2, Cambridge. • Worboys, M.F. (1995) GIS: a computing perspective. London, Taylor and Francis. • Raper, J.F. (2000) Multidimensional geographic information science. London, Taylor and Francis.