Lab3

1. What is a data model? Describe the two most commonly used data models. A data model is"a set of rules/constructs used to describe aspects of the real world in a computer". The two most commonly used data models are Vector and Raster.

2. What is topology and why is it important? Topology is, "the study of geometric properties that don't change when the forms are bent, streched or undergo similar geometric transformations". It is important because it is the most efficient method and it captures and records the relationship between features.

3. What type of data model would be best for representing hillside slope? Justify your answer. Vector Data model for the hillside slope is better due to the better resolutions for linear features and has more accurate analysis. 

4. Describe the relationship between spatial detail and cell dimension with regard to raster models. Raster models consist of "features as a set of cells in a grid". In the cell dimension on grid represents on value.The Raster model is easy to understand and create. The one downside that Raster data has, it is challenging to resolve fine spatial detail.

5. What are the four types of attribute data? Give an example of each. They are nominal, ordinal, interval, and ratio. Nominal-A set of toy cars. Ordinal- Results in a race. Interval- thermometer. Ratio- Earth's Longitude and Latitude.

6. List two types of vector data file formats. Shapefile and coverages.

7. List two types of raster data file formats. Images and Grids

 8. You can do all of the following in ArcCatalog EXCEPT:
a. Identify features

9. In the Chapter 4 exercises, does the World.mdb geodatabase contain a feature dataset? No, it does not contain a feature dataset.

10. What are the names of the feature classes contained in the World.mdb geodatabase? Cities, Countries, Disapp_area, and World30.

11. What data format does the flight_path.lyr layer file reference? It references the vector data format.

12. What are two ways to add data to an ArcMap document? One way is to click and drag the feature class onto the ArcMap, another is just by going to and clicking on add data in the table of contents of ArcMap.

13. How many features (records) exist in the dissap_area feature class? 699 records exist.

14. How can you determine this using ArcCatalog? By clicking onto the Metadata and the attribute tab.