We've heard it scores of times by now: Teachers are the most important school-based factor affecting student achievement. The evidence for this claim rests on value-added estimates involving students' scores on state-administered tests, but these tests tend to focus on basic knowledge and skill.
A more limited body of evidence extends teachers' impact into non-cognitive measures, and an article forthcoming in the Journal of Human Resources takes the next step. Its author, Matthew Kraft of Brown University, offers estimates of teacher effects on students' grit, growth mindset, and effort in class, as well as direct evidence of the relationship between teachers' impact on state test, complex open-ended academic material, and social and emotional competencies.
Kraft's evidence comes from the data generated by the Measures of Effective Teaching project. Random assignment of students to project participants in six large districts make the new findings as rigorous as possible. These findings are among the most noteworthy. The teachers who most improve students' basic numeracy skills also tend to have affect students' achievement on more complex mathematical tasks. In contrast, the teachers who most improve students' basic literacy have no special potency when it comes to students grappling with complex text. Additionally, there seems to be little relationship between teachers' ability to boost achievement on basic or complex material and their impact on students' effort, grit, or growth mindset.
Northwestern University Professor Kirabo Jackson found similar results in an analysis of North Carolina student data.
The use of value-added estimates of teachers' impact as a factor in performance evaluation or compensation has been controversial, in part, because of the narrow focus on basic skills inherent in state tests. The emerging literature on teachers' impact on complex academic content or non-academic measures, in which this new article features prominently, supports the idea that additional outcomes should inform the picture of teacher efficacy.