Viewing compactness tests

Compactness is having the minimum distance between all the parts of a constituency. The most compact districts form either a circle, square, or a hexagon.

There are a number of data quality checks contained in Esri Redistricting Online that allows you to measure whether a district plan adheres to certain standards.

Note:

Esri Redistricting Online uses WGS 1984 Web Mercator Auxilary Sphere WKID: 102100 projection when calculating compactness tests.

You can perform a compactness test that measures the following tests:

• Polygon Area Test compares the areas of each district. The area is reported in square miles.
• Perimeter calculates the perimeter of the district, including inner holes. The perimeter is reported in miles.
• Reock Test calculates the ratio of district area to the smallest circle containing the district.
• Area / Convex Hull Test determines the ratio of the area of the district to the convex hull area of the district.
• Grofman Test calculates the ratio of the district perimeter to the square root of the area.
• Schwartzberg Test is the ratio of the perimeter of the district to the perimeter of a circle of an equal area to that of the district.
• Polsby Popper Test calculates the ratio of the same area of the district to the area of a circle with the same perimeter.
• Holes determines the number of holes (geography clusters that are fully enclosed) within each district.

Steps:

1. On the Review ribbon, click Compactness Tests.

   The Compactness Tests dialog box opens. Results from the compactness test are displayed.

   Note:

   It may be necessary to click Refresh to update the compactness tests if you make changes to your district plan.