It can sometimes be hard to teach about mediation without an exemplar.  Video has been used in teaching negotiation and mediation for some time in tertiary education and also short course training.  Video has the benefit of providing students with the opportunity to watch and reflect on skills based content and these reflections can later be put in practice in face to face role-plays.

RMIT and the Victorian Bar Dispute Resolution committee have made a useful video to assist student learning about mediation.

You can find it at: 

http://www.youtube.com/playlist?list=PLyLqvrY-O1lmCwS1Ry5glz8qnOXiQsPhe