Gates Foundation officials say the most reliable systems include a balanced mix of teacher evaluation methods, including student test scores, lesson observation, and student surveys.
“If you do it right, you can generate measures that will help identify teachers [who] are having a bigger impact. That’s a really big deal,” said lead investigator Thomas J. Kane, professor of education and economics at the Harvard Graduate School of Education.
In trying to assess how best to measure teacher effectiveness, the Gates Foundation studied 3,000 teachers across the country. The research included classroom videos of 13,000 lessons, interviews with students and administrators, test scores, and experiments to test theories.
Classrooms were studied in North Carolina’s Charlotte-Mecklenburg Schools, the Dallas Independent School District, Denver Public Schools, Hillsborough County Public Schools in Tampa and St. Petersburg, Fla., Memphis City Schools, the New York City Department of Education, and Pittsburgh Public Schools.
One of the new conclusions of the final report is that having a second person, other than the principal, evaluate a teacher greatly enhances reliability.
The researchers also established a baseline for how much influence test scores should have on teacher evaluation, saying tests should not represent more than half the total teacher evaluation score, unless the district is just trying to predict outcomes on future test scores.
Vicki Phillips, director of the Gates Foundation’s K-12 education program, said the focus of teacher evaluation systems should be on giving feedback to help teachers improve.
Several districts involved in the research acknowledged that student surveys were the most controversial part of the process, and some, like Hillsboro County Public Schools in Florida, have opted to leave them out of the mix when scoring teachers.
Jean Clements, president of the Hillsboro Classroom Teachers Association, said her district decided the results of student surveys, which ask questions like “do you feel challenged to do your best work,” might not be trusted by teachers.
The researchers found, however, that student surveys help teachers improve their practice, because those results evoke the most emotions.
Test scores and principal evaluations don’t bring tears to many teachers’ eyes, Kane said. But “getting these student surveys back … hits you where your heart is.”