In 2010, Oregon Department of Education (ODE) developed a set of rubrics designed to score a state required performance assessment targeting Science Inquiry (SI) and Engineering Design (ED) skills. During the development of the rubrics, ODE invited six panels of teachers to provide feedback on an early draft of the rubrics. This case study analyzed the teachers' feedback and the revisions of the rubrics to identify the types of feedback teachers offered and how ODE used that feedback to develop the rubrics. The results showed the teachers' feedback focused on defining the skills students were asked to demonstrate and distinguishing levels of student performance. There was clear evidence that the teachers' feedback had a substantial impact on the development of the rubrics. These results suggest that teachers can add substantial value during the development of a state issued assessment tool.