Results of a study involving 450 teachers in three California school districts show that two sets of standards exist for judging the effectiveness of teacher unions. For union leaders, legitimacy means keeping promises to teachers by winning concessions from management and, at the same time, working toward a more credible and cooperative relationship with management. Teachers, however, perceive union status less as what unions are able to win than the apparent acceptance by the school board of the union as the teacher representative. Teachers' perceptions of the tone of labor relations also are strongly influenced by the way in which the administration is seen as treating the teachers themselves: being open and above board, reasonable, and innovative in school operations. The results of four multiple regressions and a path analysis have significant implications for unions and administrators. Unions must shift efforts away from militant activities and toward interpreting teachers' needs for responsible administration. Administrators should be less concerned that the union threatens managerial rights and recognize the need for innovative programs and open policy making. Teachers want both legitimate unions and good schools, and they see no conflict in having both. Eight tables and a brief bibliography are included. (IW)