In an era of increasingly rigorous state standards, teachers at all grade levels face heightened expectations to deepen their students’ understanding of mathematical concepts. Teachers may thus benefit from professional development (PD) that deepens their own conceptual understanding of math.

This report is the result of a study commissioned by the Institute of Education Sciences at the U.S. Department of Education, which examined the impact of content-intensive PD on teachers’ math content knowledge, their instructional practice, and their students’ achievement.

The key findings on the impact of the study PD on teacher knowledge, practice, and student achievement include:

• The PD had a positive impact on teacher knowledge. On average, treatment teachers’ math knowledge scores on a study-administered math assessment were 21 percentile points higher than control teachers’ scores in spring 2014, after the PD was completed.
• The PD had a positive impact on some aspects of instructional practice, particularly richness of mathematics. We assessed teachers on three dimensions of practice: richness of mathematics, which emphasizes the conceptual aspects of math, such as the use and quality of mathematical explanations; student participation in mathematics, which focuses on student mathematical contributions, explanations, and reasoning; and errors and imprecision, which focuses on incorrect, unclear, and imprecise use of math.
• Despite the PD’s generally positive impact on teacher outcomes, the PD did not have a positive impact on student achievement. On average, treatment teachers’ students scored two percentile points lower than control teachers’ students in spring 2014 on both a study-administered math assessment aligned with the content of the PD and the state math assessment.