Focus on improving teacher quality and student achievement led many state departments of education to implement research-based teacher effectiveness systems. The Teacher Professional Growth and Effectiveness System (TPGES) was implemented as the Kentucky teacher effectiveness system. This study examined teachers' and principals' viewpoints concerning the impact of TPGES on increasing their knowledge and understanding of the evaluation process and needed additional professional development at the end of the implementation year. Study results indicated mixed viewpoints concerning their knowledge and understanding of TPGES and of their viewpoints concerning additional needed professional development. In addition, researchers identified four professional development implications based on participating educators' TPGES professional development efforts. Due to the rural setting, these implications are not generalizable to all schools; however they could provide guidance for other public school educators as they work to implement successful professional development initiatives in their schools.