Even as most of the nation's 15,000 public school districts roll out new systems to evaluate teachers, many are still struggling with a central question: What's the best way to identify an effective educator?
After a three-year, $45 million research project that included Hillsborough County, the Bill and Melinda Gates Foundation thinks it has some answers.
The most reliable way to evaluate teachers is to use a three-pronged approach built on student test scores, classroom observations by multiple reviewers and teacher evaluations from students themselves, the foundation found.
"We identified groups of teachers who caused students to learn more," said Thomas Kane, a professor at the Harvard Graduate School of Education and principal investigator of the Gates study, also known as the Measures of Effective Teaching project.
The findings released Tuesday involved an analysis of about 3,000 teachers and their students in Hillsborough County, Charlotte, Dallas, Denver, Memphis, New York and Pittsburgh. Researchers were drawn from the Educational Testing Service and universities including Harvard and Stanford.
The large-scale study is the first to demonstrate that it is possible to identify great teaching, the foundation said.
Researchers videotaped 3,000 participating teachers and experts analyzed their classroom performance. They also ranked the teachers using a statistical model known as value-added modeling, which calculates how much an educator has helped students learn based on their academic performance over time. And finally, the researchers surveyed the students, who turned out to be reliable judges of their teacher's abilities, Kane said.
They used all that data to identify teachers who seemed effective. And then they randomly assigned students to those teachers for an academic year.
The teachers who seemed to be effective were able to repeat those successes with different students in different years, the researchers found. Their students not only scored well on standardized exams but also were able to handle more complicated tests of their conceptual math knowledge and reading and writing abilities.