Concern about violence in schools has resulted in numerous conflict resolution and peer mediation programs being implemented, though there is very little research examining their effectiveness. The exception is the Teaching Students to be Peacemakers program, which teaches students to be peacemakers in five steps: learning what is and what is not a conflict; negotiating integrative agreements to conflicts; mediating classmates' conflicts; implementing the program; and receiving ongoing training. Between 1988-00, the paper's authors conducted 17 studies on the effectiveness of conflict resolution training in eight different schools in two countries. Participating students ranged from kindergarten through ninth grade and attended rural, suburban, and urban schools. Data collection involved observations, interviews, conflict report forms, written and oral responses to conflict scenarios, role playing responses to conflict scenarios, and actual conflicts created with classmates. Results indicated that students learned the conflict resolution procedures taught, retained their knowledge throughout the school year, applied the conflict resolution procedures to actual conflicts, transferred the procedures to nonclassroom and nonschool settings, used the procedures similarly in family and school settings, and, when given the option, engaged in problem solving rather than win-lose negotiations. Appended are 2 tables and 17 Peacemaker Studies References. (Contains 43 references.) (SM)