The purpose of this study was to identify the processes that have been used for implementing the alternative scheduling plan of block scheduling in high schools. The study attempted to discover what professional development activities were used for the change, if teachers altered instruction, and what additional staff development was needed. The qualitative method of case study research was selected for the study. The investigator chose five public high schools, representing city and county systems and different professional development budgets and types of instructional support. Central office administrators who were responsible for the implementation of block scheduling, principals, and a purposeful sample of teachers were interviewed. Utilizing interview transcripts, field notes, and records, case studies were formulated for each school. A cross-site analysis was also developed. This aspect of the study focused on several themes that emerged from the case studies. These themes included reasons for the scheduling change; implementation procedures; professional development strategies; effects on instruction, students, and schools; and procedural and staff development needs. The conclusions of the study were as follows: a concern for students prompted the change; considerable effort was devoted to implementation; the 4 x 4 semester plan was the most common configuration; a considerable difference existed in the amounts schools spent for professional development; and staff development was integral to implementation. Additional conclusions were that block scheduling had both positive and negative effects on instruction; some teachers altered instruction with the schedule; the majority of students preferred a block schedule instead of a traditional one; the plan had a positive impact on the discipline, course offerings, and learning atmosphere of a school; and changes in implementation and professional growth would enhance the innovation. These conclusions will assist educators in developing and implementing procedural strategies and professional development plans for block scheduling, as well as other reform efforts
