Ann Johnson
ajohnson@esri.com
Environmental Systems Research Institute (ESRI)
Objective:
To give students a “feeling” of what is happening in the computer for
points, lines and polygons. While not
strictly what is happening in any particular software, this module helps students to
understand they are not looking a finished map “image” but something the
software redraws (Arcs or lines with a direction, etc.)
with each update. Also it helps
students to understand topology and what is happing in a database to determine topological
relationships.
Time:
If the
PowerPoint is used, approximately 15 minutes to introduce theory and about 20 minutes to
fill out Topology Table.
Materials Needed:
PowerPoint Software, Paper and Pencil Topology exercise, Transparency of Topology
diagram.
Grade Level: High
school to University Introductory GIS course
Description of Activity: Go through and either present Spatial Data
Formats PowerPoint or talk about points, lines and polygons and how the computer stores
and searches them for topology relationships. Then
have students fill out Table and answer questions. Use
Transparency and fill in with correct answer – engage students with questions
regarding directions, nodes, and have them discuss what a Network would be (connectivity
and direction).
Optional Extensions: You might give students a simple paper with
polygons on it and have them create and number or identify Nodes, Arc, Polygons and their
relationships
Contact for More Information: Ann B. Johnson, ajohnson@esri.com