The nine Federal districts were Eastern North Carolina, Oregon, Southen Texas, Northern Georgia, Eastern Pennsylvania, Eastern Kentucky, Northern California, Eastern Missouri, and Eastern Washington. The study developed information through open-ended interviews with judges, full-time magistrates, and practicing attorneys from a variety use firms in the nine districts; data were also collected to assess the rates of appeals of magistrates' actions for statistical year 1982. The study's underlying premise was that magistrates' functions develop in the context of a district's approach to court administration and case management. The findings indicate two distinct overall approaches to court administration and case management among the districts. Some districts have a district-wide approach to court processes; in these districts, magistrates are generally included in the court's administrative decisions. In other districts, judges are expected to develop their own approaches to pretrial monitoring; in these districts, judges uses magistrates according to their own management styles. Three models of magistrate use were identified. In some instances, magistrates are used as 'additional judges' having a peer role in court administration and docket management. In other contexts, magistrates are used as specialists in some demanding and ongoing area of the docket. Some districts use magistrates as team players who develop discretionary responsibilities for the pretrial phases of case processing. A review of the outcome of magistrates' work indicates that parties do not regularly challenge magistrates' reports and recommendations on dispositive motions or orders on nondispositive motions. Overall, the use of magistrates was found to be a cost beneficial way to shorten case processing time. Appendixes contain the interview questionnaires and additional data. Twenty-one tables are included.