Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Reviewing and Understanding Actions on the Table of Contents

____ 30. Look at getting information from entries in the table of contents (T/C): Drag Soils to the bottom of the Table of Contents. Click the box containing the check mark next to Landcover. Note the result. Click it again so the layer is on. Click the box with the little minus sign in front of Landcover, and note that the symbol that represents Landcover goes away. Click the little plus sign. Click the List By Source tab at the top of the T/C. Note that you are given the path, in a hierarchical form, to each data set. Experiment by clicking the boxes that contain either plus (+) or minus (–) in the T/C. Understand these actions. Leave all entries fully expanded. Clear all selections.

____ 31. Press the List by Selection tab at the top of the Table of Contents. The check boxes here let you set the layers that are selectable. That is, if a layer’s box isn’t checked, the Select Features tool cannot select features from that layer. Prove this to yourself by clicking the “Click to toggle selectable” box that is associated with Landcover to make Landcover un-selectable. It will appear in a different part of the T/C. Now click the map with the Select Features tool. Features will be selected, but they will be from the soils layer underneath. Turn off the display of the soils layer by clicking “Click to toggle visibility”. Now notice that Select Features has no effect. The lesson: For Select Features to work, a layer must ...