This study examines the impact of intensive mathematics professional development (PD) on teachers’ knowledge and teaching skills for seventh-grade mathematics in rational number topics, such as fractions, decimals, percent, ratio, and proportion. The intensive PD studied includes over 100 hours of support in the form of summer institutes, seminars, and in-school coaching. Schools in 12 districts participating in the study were randomly assigned to receive the intensive PD activities or only the PD activities normally provided by the district. All seventh-grade teachers teaching at least one regular seventh-grade mathematics class within the treatment schools were offered the intensive PD during the first year of implementation. In six of the districts, the intensive PD was provided to eligible seventh-grade teachers in the study schools for a second year.

Findings after two years of implementation include:

• The intensive PD was implemented as intended, but teacher turnover limited the average dosage received. On average, the treatment teachers in the second-year impact sample received 68 percent of the full intended dosage. Because some teachers left the study schools and others entered as the study progressed, not all teachers had the opportunity to experience the full dose of PD.



• There was no evidence that the intensive PD resulted in improved teacher knowledge. There were no significant impacts on teachers, scores on a specially constructed teacher knowledge test or on either of the subscores. On average, about 75 percent of teachers in both the treatment and the control groups correctly answered test items that were of average difficulty for the test instrument.



• There was no evidence that the intensive PD had led to improvements in student achievement in rational numbers knowledge. Students taught by teachers in the intensive PD group and students taught by teachers in the control group performed similarly on a rational numbers test.