Increasing the Odds - How Good Policies Can Yield Better Teachers National Council on Teacher Quality
"Two recent reviews of the research found that a teacher's level of literacy as measured by vocabulary and other standardized tests affects student achievement more than any other measurable teacher attribute, including certification status, experience, and the amount of professional development that a teacher receives.
"These summary findings were based on numerous robust studies spanning many decades that looked at the impact of literacy on student achievement, all finding that a teacher’s level of literacy is a strong predictor of student achievement."