Research Findings: Developmental evaluation is a process in which researchers and program implementers communicate collaboratively to produce an evaluation that is attuned to critical program issues, provides useful data during program implementation, and results in rigorous methodology and findings informed by program conditions (M. Q. Patton, 1997). The implementation evaluation of Indiana's Paths to QUALITY™, a statewide quality rating and improvement system (QRIS), provides examples of this developmental evaluation process. Researchers and program leaders engaged in collaborative evaluation planning, QRIS standards validation, and review of formative data about the experiences of child care providers, parents, and children in the system. Frequent communication between evaluators and program implementers during the 4-year evaluation project resulted in (a) QRIS leaders having timely data that they used to fine-tune the program and (b) evaluators making needed adjustments in the research design and making more plausible interpretations of results. Examples of the collaborative evaluation process are given, with reflective comments provided by the state QRIS administrator. Practice or Policy: The collaborative strategies used in the implementation and evaluation of this state-level child care QRIS may be useful for other states or localities as they plan large-scale early care and education systems.