To clarify the role of collective bargaining in defining and reforming local school district staffing policies, an analysis was made of 144 teacher contracts gathered from a stratified, random sample of districts. In five of these districts, selected for their diversity on a number of variables (state, region, size, labor history, contract, and union affiliation), documents were analyzed, offices and schools visited, and interviews conducted with 187 teachers, principals, union leaders, and central office administrators. The analysis of contract contents suggests that (1) collective bargaining agreements are neither as comprehensive nor prescriptive as some might believe; (2) much contract language about staffing specifies the prerogatives of management; (3) in some cases, contract language increased the standards of staffing beyond those prescribed by state law; (4) seniority was less prominent than expected; and (5) principals' rights to manage the staffing of their schools were not clearly defined by contract. Studying reform in the five sample districts revealed that districts with a history of cooperative relationships dealt more successfully with initiatives for change. Proposals more likely to be adopted were those with local origins and support for more time for instruction, more stability for schools, and more instructional autonomy for teachers. (MLF)