This case study of a Colorado school district sought to assess the process and outcomes of administrative leadership in implementing school effectiveness research on time-on-task classroom strategies. The study examines the interrelationship of conditions bearing upon the change effort and focuses on those changes affecting the district's personnel, policy, and procedures. The district's program emphasized two related variables that characterize effective schools: teacher and student use of time and the instructional leadership of administrators, particularly in reinforcing teachers; implementation of time on task (engaged time) from classroom observations. The following methods provided the data record: (1) interviews with the superintendent, school administrators, elementary and secondary teachers, and program trainers; (2) verbatim records of an inservice training session; and (3) pertinent documents from school and district sources. Three findings, which emerged from data analyzed by the constant-comparative method, are offered as caveats to other districts implementing school effectiveness programs. First, principals' engaged-rate observations provide little meaningful reward or corrective feedback to teachers. Time spent actively engaged in a task is secondary to its appropriateness and to the student's success. Second, principals' understanding of the instructional process is limited by an emphasis on such observations. Third, the importance of allowing adequate time for the change process is highlighted by this study's results. Researchers cannot produce accurate assessments of school effectiveness programs until consistency in implementation is established across sites. The field's constructs are sufficiently nebulous to cause confusion in interpretation. This investigation demonstrates the need for descriptive studies that offer operational definitions of school effectiveness variables in practice. (CJH)