This paper examines the redesign of evaluation components for a teacher professional development project funded by the National Science Foundation. It focuses on aligning evaluation instrumentation and strategies with program goals, research goals and program evaluation best practices. The study identifies weaknesses in the original (year 1) program evaluation design and implementation, develops strategies and tracks changes for year 2 implementation, and then reports enhancement of findings and recommendations for year 3. It includes lessons learned about assessment and evaluation over the project lifespan, with implications for research and evaluation of a range of related programs. This study functions as a classic illustration of how critical it is to observe first principles of assessment and evaluation for funded programs, the risks that arise when they are ignored, and the benefits that accrue when they are systematically observed. (Contains 3 tables.)