CCSSO received a grant from the National Science Foundation to plan and conduct a meeting that would bring together research and evaluation experts and state leaders for professional development in mathematics and science education. In April 2008 CCSSO invited 10 leaders in the field of research and evaluation of teacher professional development to meet with state education program managers and evaluators to present and discuss models for evaluating effects of professional development. Recent developments with state data systems, use of experimental designs in education research, and use of surveys and assessments has provided the tools for improved methods of evaluating professional development. The two-day conference provided an opportunity for leaders from states to learn how they can apply the models in their state programs. The following summary of presentations and discussions from the April conference are intended to provide a wider audience with information about its recommendations and results.