In 1995, the National Science Foundation (NSF) contracted with principal investigator Iris Weiss and an evaluation team at Horizon Research, Inc. (HRI) to conduct a national evaluation of the Local Systemic Change for Teacher Enhancement program (LSC). HRI conducted the core evaluation under a $6.25 million contract with NSF. This program evaluation project, called the LSC core evaluation, had an overarching program-wide focus that included all 88 local LSC projects. The LSC core evaluation was a large, multisite program evaluation that included multiple data-collection and information-dissemination activities. Each local LSC project was required to have a project-level evaluator, to collect information by using predesigned data-collection instruments developed by HRI, and to report findings to the core evaluation on a regular basis. This case study describes the relationship between project-level involvement in the LSC core evaluation and the use of the core evaluation by project leaders and evaluators.