Over the span of ten years, a National Science Foundation‐funded partnership effort has collected and analyzed multiple forms of evidence, both direct and indirect, about improved teaching of mathematics within Rapid City Area Schools. This article describes the project\u27s impact on K‐12 teaching and factors contributing to that impact. The authors argue that improvements in teaching are attributable largely to a robust infrastructure established to support teacher growth. Direct evidence includes classroom observations conducted by the project\u27s external evaluation team. Indirect evidence exists in the form of data on student outcomes: achievement on the state\u27s multiple‐choice accountability measure and achievement on project‐administered performance assessments
