A two-part research and evaluation study was conducted to examine an elementary (K-8) school district's implementation of a computerized instructional management system, the "Computer-Managed Instruction/3000" (CMI), as a means of facilitating the assessment and updating of student mastery of 78 district-defined curricular objectives. The testing system consisted of a data bank of tests based on the district mathematics objectives, equipment to machine score student answer sheets, and reports detailing student mastery of the objectives. This system was piloted by administrators and teachers at four district-selected schools. A detailed interview schedule was developed to elicit such information as background in the district; knowledge of the CMI system, including how, why, and by whom it was selected; uses of the system for testing and instruction; technical problems; potential uses of the system; and its effects on school organization and instruction. Analysis of the responses of 49 school staff members--principals, resource teachers, teachers, and clerical staff from both pilot and nonpilot schools--identified a number of factors as keys to the implementation of the program: (1) planning; (2) communication and awareness of its purpose; (3) support from key personnel; (4) training; (5) technical issues and procedures; and (6) rewards and incentives for using the system. When viewed positively, these factors operated as facilitators to the acceptance and implementation of the system; however, when viewed negatively, the same factors operated as barriers. Data summaries are provided in Tables 1-7. The Study Interview Schedule and the Coding Matrix are appended, and references are provided. (DJR)