Mediation is most successful when the parties’ advocates/advisors are knowledgeable and skilled in the principles of the mediation process and negotiation theories. Mediations can fail when party representatives act as if they were in a courtroom rather than in a negotiation. Mediation presents unique problem-solving opportunities in which representatives can assist their clients to reach faster, cheaper and/or better outcomes with the assistance of a mediator. They can help their clients achieve outcomes that may be unattainable in a courtroom or arbitration tribunal. But to do that, they need a different set of knowledge and skills. IMI has therefore developed Substantive Criteria for Mediation Advocates/Advisors Competency, which includes both General Knowledge and Practical Skills requirements, as a guidance to programs in designing knowledge/skills assessments.