How do I partition users by percentage?

Users are partitioned in the Level or Form Settings by adding a % of References Filter in the Users Assigned and RefID Partitioning section. 

Note: partitioning by percentage is not done by dividing the total assigned users by 100 and then applying the result as a direct percentage for each user. For example, if you wanted to split assignments for two reviewers, it is assumed that both would be assigned 50% with the filter. However, filtering this way will assign the same 50% of references to both reviewers. 

The proper method is to assign 50% to one reviewer. The second reviewer would be assigned 100% of references and must add a NOT 50% filter as well. So in the end, one reviewer is assigned to 50% and the other is assigned to 100% - 50%. 

In a scenario with three reviewers, assign one reviewer to 34%, a second reviewer to 67% and NOT 34%, and a third reviewer to 100% NOT 67%. 

Partitioning by percentage may not result in precise but proximal numbers, and does not address references that have already been processed. Remember to reconcile references after changing user assignments in your Workflow.