Using concepts from the evaluation literature, this case study describes the instrumental, conceptual, and political influence of the Head Start National Reporting System (NRS) and on-going child assessments in a local Head Start program. This study found that a local program intentionally aimed to limit the influence of the NRS. The NRS validated the program's performance for the program administrators and local governing bodies. It had no impact on teaching and learning, and was not used to make decisions to guide local program improvement. On-going child assessments were more widely valued within the local program. These assessments had some impact on teachers' individualization of instruction for children, and managers made some effort to use program-level findings to inform program development. Similar to the NRS, the on-going child assessments were also used to provide accountability with local governing bodies. Based on these findings, implications for the use of local-level systems in early childhood programs are discussed. (author abstract)