Students learn more from tough teachers, new study finds

High grading standards benefit students for years

Cambridge, Mass., Feb. 04, 2020 (GLOBE NEWSWIRE) -- Grade point averages have soared over the last two decades while other measures of academic performance—such as SAT exam and the National Assessment of Educational Progress—have held stable or fallen. Is grade inflation cause for concern? In a new research article for Education Next, Seth Gershenson of American University reports that “easy As” are not a victimless crime: students learn more from tougher teachers, and they continue to do better in math classes up to two years later.

Using data from North Carolina collected during the period 2006-2016, Gershenson, in collaboration with the Thomas B. Fordham Institute, compared the course grades and end-of-course exam scores for about 350,000 8th- and 9th-grade students taught by roughly 8,000 Algebra I teachers, categorizing teachers into quartiles of easy to tough graders. He then tracked student achievement on Algebra I end-of-course exams, longer-term achievement in Geometry and Algebra II, high school completion, and college enrollment.

Read the article. Among the key findings:

  • Students learn more from teachers with higher grading standards. Teachers with the most rigorous grading standards increase student test scores by 17 percent of a standard deviation compared with their peers with easiest grading standards—an increase equivalent to a little more than six months of learning. Teachers in the middle of the grading standards distribution also improve student test scores more than teachers with less strict grading standards.
  • Benefits of high grading standards persist in later math courses. Students whose Algebra I teachers had the highest grading standards continued to earn higher test scores in Geometry (an increase of 7 percent of a standard deviation) and Algebra II (9 percent of a standard deviation), courses taken one and two years later. These effects translate into differences of about 2.5 and 3.2 months of learning, respectively.
  • Benefits consistent across student subgroups and school types. On average, having an Algebra I teacher in the top 75 percent of the grading standards distribution improves achievement for all student subgroups by about 10 percent of a test-score standard deviation compared to having a teacher with the easiest grading standards. Similarly, teachers with higher grading standards benefit students in all types of schools: middle and high schools; suburban, urban, and rural schools; and schools that predominantly enroll economically advantaged and economically disadvantaged students. Students attending suburban schools benefit somewhat more from higher grading standards, with an effect of 12 percent compared to 7 percent for urban schools.
  • Grading standards are driven by teacher characteristics. The average grading standards of teachers who attended selective colleges, as defined by Barron’s Profiles of American Colleges, are 50 percent higher than those of teachers who earned their undergraduate degrees from less-selective schools. Years of experience also increases teachers’ grading standards, particularly during a teacher’s first 15 years.

“These findings are a call to action,” Gershenson writes. “We know that teachers’ grading standards are an important component to their students’ success, and we have started to identify the characteristics of teachers associated with higher standards.” He recommends that school leaders monitor teachers’ grading practices and suggests that grading standards can be used as a measure of teacher effectiveness.

About the Authors: Seth Gershenson is an associate professor at the School of Public Affairs at American University.

About Education Next: Education Next is a scholarly journal committed to careful examination of evidence relating to school reform, published by the Education Next Institute and the Program on Education Policy and Governance at the Harvard Kennedy School. For more information, please visit



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