At a workshop for the Ohio Commission for Dispute Resolution, Tricia S. Jones, Ph.D., presented "Looking for Success: Evaluating Peer Mediation and Conflict Resolution Education Programs", based on a book in progress. The authors evaluated several schools' programs. Read about the study here:
I wrote my Master's Degree Thesis on Computer-Assisted Peer Mediation training about 10 years ago which had an evaluation component in it. I was comparing traditional peer mediation training programs to one with an interactive computer program. I have attached the thesis for anybody interested in this topic.