This research report reviews some of the highlights of the ongoing longitudinal evaluation of the REDRESS® program at the United States Postal Service, the world's largest employment dispute resolution program. These results represent the first systematic data on how a mediation program can function in the workplace setting. This synopsis of the REDRESS® evaluation compares results between the outside neutral and inside neutral conflict resolution systems, explores the role of representation in mediation, and examines the impact of mediation on formal EEO discrimination complaint filings.