For many districts, evaluation is an afterthought to implementing a new initiative. Educators participate in professional learning experiences, apply what they learn to their practice, and then, at some point, school and district staff begin wondering if the initiative is making a difference. Then they scramble for nuggets of data that provide any evidence of effectiveness. There is another way. A partnership between educators in Metro Nashville Public Schools in Tennessee and external evaluators with Regional Educational Laboratory Appalachia (REL Appalachia), with funding from the Institute of Education Sciences, used a well-defined process to evaluate the implementation and effectiveness of a new data use initiative from its inception. This article highlights how the partnership approached evaluation, the process external evaluators used to build internal evaluation capacity among the Metro Nashville district staff, and the valuable lessons partnership members learned about fostering successful evaluator-practitioner partnerships.