Lab #3: Data Formats & Models

I. Answer the following questions based on Bolstad Chapter 2 and lecture.
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 and represent aspects of the real world in a computer. Geometric/Geospatial Data- defines spatial location and extent using usually coordinates or pair of numbers. Attribute data- captures non spatial info in an attribute table.

2. What is topology and why is it important?
The study of geometric properties that do not change when the forms are bent, stretched or undergo similar geometric transformations

3. What type of data model would be best for representing hillside slope? Justify your answer.
Geospatial data would best represent a hillside slope when constructing a model of the hillside with spatial information

4. Describe the relationship between spatial detail and cell dimension with regard to raster models.
With a raster model cells represent the given information, with each cell having equal dimensions but different numbers of spatial info for each cell.

5. What are the four types of attribute data? Give an example of each.
Nominal- descriptive categorical data such as a house and a tree.
Ordinal- ranked and ordered data such as lists of smallest to biggest.
Interval- ordered data, with absolute differences in magnitude and arbitrary zero. Range of data along a live
Ratio- ordered data, with absolute differences in magnitude and absolute zero. A number line defined at an absolute zero

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

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

II. Answer the following questions using the data/tutorials supplied in Ormsby
Chapter 4.
8. You can do all of the following in ArcCatalog EXCEPT:
c. Select features

9. In the Chapter 4 exercises, does the World.mdb geodatabase contain a feature dataset?
no

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?
Raster format

12. What are two ways to add data to an ArcMap document?
Click and drag the data from ArcCatalog to the TOC in ArcMap

13. How many features (records) exist in the dissap_area feature class?
699
14. How can you determine this using ArcCatalog?
By accessing the metadata

15.