Drawing on interviews with 180 staff members from 45 public high schools in 15 states, this document examines the advantages and disadvantages of teacher participation in shared decision making. The settings of six high schools that had structured mechanisms for teacher participation in school decisions are described, and problems that emerged during shared decision making processes are presented: (1) conflicts between who participates and who does not; (2) conflicts among participants; and (3) internal conflicts--new and old ideas within the same individual. The problems caused by confusion regarding the locus of final decision authority are reviewed, and the need for teacher training in the content of issues faced by decision making bodies, in the processes of decision making, and in negotiation skills is explained. Next, the development of a school culture that supports participation and provides a sense of mutual respect and trust is discussed, and one school's collective management procedure is cited as an example. A final section discusses the potential of shared decision making given clear definition of staff members' roles and the organization's overall purpose. (20 references) (CLA)