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1. In the Contents pane, click and hold the CensusHGAC_tracts layer name and drag and drop it above the HGAC_Major_Roads layer.
   
   You will notice that, in the Map view, the CensusHGAC_tracts layer is now drawn in on top of the HGAC_Major_Roads layer, meaning that the freeways are no longer visible. It is possible to add transparency to the super neighborhood layer or to symbolize it with a bold outline and a hollow fill, but, in general, it is best to have polygon layers at the bottom of the drawing order, so we will return the layers to their previous order.
   
   

2. In the Contents pane, click and hold the CensusHGAC_tracts layer name and drag and drop it beneath the HGAC_Major_Roads layer, but above the Topographic basemap.

   The check boxes to the left of each layer name toggle the visibility of each layer.
   
   

   Note
   Because the basemap is a solid image, any layers beneath it will not be shown at all, so ensure the basemap is always at the bottom of the layers in the Contents pane.

3. Uncheck the HGAC_Major_Roads layer to turn off its visibility in the map view.
4. Check the HGAC_Major_Roads layer to turn its visibility back on in the map view.

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1. In the Contents pane, right-click the HGAC_tracts layer name and select Attribute Table.
   
   A table view now appears docked beneath your map view. Each row, or record, in your table corresponds to exactly one super neighborhood census_tract polygon on the map. Each column, or field, in your table represents a variable describing the super neighborhoodscensus tracts.
   
   Every geodatabase feature class has two to four default fields, which cannot be edited or deleted. The leftmost OBJECTID field is a unique ID that is automatically numbered from 1 to the total number of features at the time of creation. In this particular case, the field is called OBJECTID_1, because there was a preexisting OBJECTID field at the time this data was imported to geodatabase format by the City of Houston. The  The Shape field indicates whether the feature geometry contains points, lines, or polygons.
   
   
2. In the table view, use the scroll bar at the bottom to scroll to the far right of the table.
   
   The other two default fields are the last Shape_Length and Shape_Area fields which contain the perimeter and area of the super neighborhoodscensus tracts, respectively. A line feature class will only contain the Shape_Length field and a point feature class will not contain either field. The units of these fields correspond to the units of the projection in which the data coordinates are stored.
   
   
3. In the Contents pane on the left, double-click the Census_2010_By_SuperNeighborhood HGAC_tracts layer name.
4. In the 'Layer Properties' window, in the left column, click the third Source tab.
5. At Scroll to the bottom of the window , and click to expand the Spatial Reference section.
6. Use the scroll bar on the right to scroll to the bottom of the metadata through the metadata.
   
   Within the Spatial Reference section, notice that the geographic coordinate system is WGS 1984 and that no projected coordinate system is listed. Therefore, the layer is unprojected, meaning the data coordinates are located on the three-dimensional surface of the globe and you can see the Angular Unit is listed as Degrees (or decimal degrees.) projected coordinates system is NAD 1983 StatePlane Texas S Central and the linear unit is US Survey Feet. Therefore, the Shape_Length field is displaying decimal degrees and the Shape_Area field is displaying square decimal degrees, which is why the numbers are so low. Before measuring distance or area, the data layer should be projected onto a two-dimensional surface. The resulting projection will have a Linear Unit, such as feet or meters. The process of projecting is further covered in the feet and the Shape_Area field is displaying square feet. Before measuring distance or area. More information about projections is available in the Introduction to Coordinate Systems and Projections course tutorial.
   As indicated by the layer name, the
   The majority of the remaining fields contain 2010 census data that was aggregated to the super neighborhood census tract level by the City of Houston, since that is not a geographic unit at which the Census Bureau provides data.
   
   
7. Scroll back 
8. Double-click the 'Name' field header to sort the neighborhoods alphabetically.
9. To select a neighborhood from the table, click the gray square to the far left of each row.
10. To select an adjacent section of records, hold down Shift and select a record below or above the currently selected record to automatically select all records in between.
11. To add or remove individual records from the selection, hold down Ctrl and select another record.
    
    Notice in the bottom left corner of the Census_2010_By_SuperNeighborhood attribute table, it indicates the number out of 88 table records (and corresponding map features) that are currently selected.
    
    
    
    The two buttons to the left allow you to toggle between 'Show all records' and 'Show selected records'.
    
    
    
    Note that if 'Show selected records' is active and no records are currently selected, the table view will appear empty. Toggle back to 'Show all records' to view the table.
    
    
12. At the top of the Census_2010_By_SuperNeighbrhood table view, click the Clear button.
    
    
    
    
13. Close the attribute table.
    
    

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