Arbitration of your indexed census occurs when a specific data field from Indexer A and Indexer B do not concur. The arbitrator looks at the census batch and both indexers inputs. The arbitrator then selects the data that appears to be most correct.
After a batch is arbitrated the batch is available under the indexers Arbitration Results tab. Each listed batch can be opened so the indexer is able to review the arbitration results.
All indexers should open the arbitrated batches to learn where they are making errors.