Discussion Questions

1. What are data models and what do they have to do with analysis?
2. All of the geographic data models are based on discrete object/ vector or field/ raster systems.  List the eight different models and their general application areas.
3. What is a layer?
4. Describe three problems with CAD systems for geographic data applications.
5. What is the problem with the non-topological graphical model that is used for simple mapping?
6. Is the image data model raster or vector? Why?
7. Raster attributes store different types of data including integers and floating point.  What sorts of datasets can you store using each of these systems?
8. How might you store multiple attributes in a raster system?
9. Metadata about rasters are stored in headers.  What information is stored in these headers?
10. Rasters are big files.  How does the computer deal with this?  What are the different methods?
11. What is the problem with using MrSID for DEMs and possibly other raster datasets?
12. In the vector model each feature is first classified into one of 3 geometric types including points, lines, and polygons.  What is the definition of each?
13. Simple line and polygon features are sometimes called the spaghetti model.  Why and what are its limitations?
14. What is topology and why is it necessary?
15. What is the definition of a polygon in the topological vector model?
16. What two tables are necessary for polygon-line topology? Describe each.
17. How does polygon topology avoid slivers?
18. What is planer enforcement?
19. What is contiguity and how is it specified through left-right topological structure?
20. What do RDBMSs have to do with managing attribute data in a GIS?
21. How are the RDBMS ID and label point used to relate or join spatial and attribute data?
22. What are some typical government applications of topological GIS?
23. How does network analysis use points and lines to model flow?
24. What is linear referencing?
25. What is an event along a route?
26. What is dynamic segmentation?
27. What is a TIN and what type of data is it used to model?
28. What are mass points and how are they used in Delaunay triangulation?
29. What are the advantages of TINs?
30. Explain TIN topology.
31. Geometry-centric geographic data models do not support sophisticated analysis and defining behaviors and relationships of geographic objects is difficult.  What is an object data model?
32. What are objects and object classes?
33. What are encapsulation, inheritance, and polymorphism?
34. What are range and coded value attribute rules in an object model?
35. What are connectivity rules in an object model?
36. What are geographic rules in an object model?

Department of Geography Home Page