As part of a district-wide longitudinal study of the implementation of a science curriculum innovation, researchers developed case studies of a sample of nine elementary schools in the Jefferson County School District, a large suburban system in Colorado. The study applied the Concerns-Based Adoption Model, which assumes that change is carried out by individuals in two general stages, the first involving stages of concern about the innovation, the second comprising levels of use of the innovation. Both quantitative and qualitative data were gathered, including survey assessments of teachers' concerns and use levels and ethnographic descriptions of the activities of district and school staff. Among the variables examined were teachers' attitudes and concerns, their previous experience with innovations, presence in the school of an innovation specialist, team teaching, school building architecture, students' socioeconomic status, and school principals' attitudes about the innovation. Analysis showed the nine schools fell into three groups, one concerned about managing the innovation, one concerned about the innovation's impact, and the last having a mixture of the two concerns. Principals' levels of support for the innovation and activities as change facilitators were the main factors determining the school's type of concern. (RW)