The FMCS provides mediation services to industries engaged in interstate commerce, private nonprofit health facilities, and Federal Government agencies involved in labor disputes. The mediator brings management and labor together and creates an environment conducive to the attainment of a settlement. FMCS mediators -- most of whom come to mediation from unions, labor relations management, or government -- work independently and are seldom observed by supervisors or peers. The current FMCS mediator performance appraisal system focuses on the volume of activities performed and neglects the identification and measurement of mediator behaviors linked to performance effectiveness. In addition to focusing on quantitative aspects of a mediator's performance, the proposed performance appraisal system involves the identification and measurement of specific, relevant, and controllable mediator behaviors. Appraisal techniques include labor and management evaluations, self-appraisal, and supervisory assessment. 2 figures and 19 footnotes.