Grading teachers on how their students perform remains controversial.
Critics argue that it may discourage teachers from taking on the neediest students, push educators to teach to the test, weaken non-tested subjects, and fail to account for outside factors that affect students.
The tests, critics say, are imperfect measures of student learning and were not designed to evaluate teachers.
"The hope is by improving the quality of teachers, you will increase learning," said Jonah Rockoff, a Columbia Graduate School of Business professor who researches evaluations. "We don't have the definitive study saying this policy will work."
Consensus is also lacking on how much - or how little - test scores should count.
"That is very much up for debate," said Sabrina Laine, director of the National Comprehensive Center for Teacher Quality, a federally funded technical-aid organization.
She said her group advised using multiple measures of teacher effectiveness.
Tyler said a study he did of Cincinnati's observation-centered evaluations showed links between high teacher marks and student achievement.
Another recent study found student surveys another promising evaluation tool.
Many officials and education stakeholders feel the need to act now. The desire to weed out bad teachers and help others improve is fueling a sense of urgency.
Studies say the most important school-based factor in children's success is good-quality teachers.
There is a widespread perception that many current teacher evaluations are flawed. Some research has found the vast majority of teachers get positive reviews.
In May, New York's Board of Regents voted to make student progress on state tests count for up to 40 percent of teachers' evaluations.
