Newly emerging research is beginning to shed light on the extent to which disadvantaged students have access to effective teaching, based on value added measures. "Value added" is a teacher's contribution to students' learning gains. Because individual researchers have varied in their presentation of this evidence, it is challenging for practitioners to draw lessons from the data. This brief highlights and summarizes three recent IES studies.

The brief found that:

• Disadvantaged students received less-effective teaching on average. Based on data from 29 districts in grades 4-8 and two states in grades 4 and 5, disadvantaged students received less-effective teaching in a given year than other students in those grades. The average disparity in teaching effectiveness was equivalent to about four weeks of learning for reading and two weeks for math. For context, the overall achievement gap for disadvantaged students in grades four through eight is equivalent to about 24 months in reading and 18 months in math. Study authors estimate differences in teaching effectiveness for one year represent 4 percent of the existing gap in reading and 2 to 3 percent in math.
• Access to effective teaching varied across districts. The size of the differences in effective teaching in a given year between disadvantaged and non-disadvantaged students varied across the 29 districts studied. The disparities for each district ranged from no statistically significant difference to a difference equivalent to 13 weeks of learning in reading and math in grades 4 through 8.