Caliper Mapping and Transportation Glossary

DEFINITION

What are Ensembles?

Ensembles are groups of randomized redistricting plans created using a proprietary implementation of the ReCom method of the Markov chain Monte Carlo algorithm. These plans can be compared to any proposed redistriciting plan to determine how random or how gerrymandered it is.

The outcomes of the precinct-level elections are superimposed to decide how many seats each group should have gained under that strategy, and the results are plotted on a bell curve. If a particular plan on this bell curve is an extreme outlier, it is considered strong evidence that the plan may intentionally have been gerrymandered to achieve a particular partisan outcome. The outcomes of the precinct-level elections are superimposed to decide how many seats each group should have gained under that strategy, and the results are plotted on a bell curve. If a particular plan on this bell curve is an extreme outlier, it is considered strong evidence that the plan may intentionally have been gerrymandered to achieve a particular partisan outcome.

Maptitude for Redistricting Ensemble Analysis

Using Maptitude for Redistricting for Ensemble Analysis

Maptitude for Redistricting is the professional tool for political redistricting. It is used by a supermajority of the state legislatures, political parties, and public interest groups. Designed with the help of redistricting professionals, state legislatures, and political parties, Maptitude for Redistricting has the features redistricters want, such as ensemble analysis, and is easy to learn and use.

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