American Federation of Teachers President Randi Weingarten testifies before Congress in 2008. REUTERS/Mitch Dumke

A New Mexico judge has temporarily barred schools from using the state’s controversial test-based teacher evaluations to make personnel decisions, finding that the system appears not to be objective and uniform as required by law.

The preliminary injunction means that for the time being, teachers cannot lose their licenses for low ratings, and nor can they receive merit wage increases for high ratings.

The injunction will remain in place until Judge David K. Thomson of Santa Fe’s district court can hear and decide the full case brought by the American Federation of Teachers, which argues that the evaluation system should be dismantled because it is arbitrary and unfair.

[Contentious teacher evaluations moving from legislatures to courts]

AFT President Randi Weingarten hailed the judge’s decision to grant a preliminary injunction, calling it a “decision that will resonate through communities across America.”

“Judge Thomson recognized that New Mexico’s teacher evaluation system is deeply flawed, and deprives students of the high-quality educators they deserve while also hurting and demoralizing teachers — the very people we rely on to help students,” Weingarten said in a statement.

New Mexico is among a growing number of states that use complex and controversial algorithms — called “value-added models” — to figure out how much of a student’s learning can be attributed to their teacher.

The theory appears to be valid, Thomson wrote Wednesday. But in practice, New Mexico’s program has been riddled with data errors, a lack of transparency and other problems, he wrote.

“The problem at this stage in the litigation is that New Mexico appears to be a Beta test where the teachers bear the burden for its consistent and uneven application,” Thomson wrote. He wrote that the union had showed a “substantial likelihood of success” in proving that the evaluations violate state law.

In New Mexico, up to 50 percent of teachers’ evaluation are based on test scores.

The teachers union had initially asked for a broader injunction that would have prohibited state and district officials from using the evaluation system at all. The union later narrowed its request, asking only that teachers be protected from any sanctions flowing from the evaluations.

So the New Mexico Public Education Department can continue to require teachers to be evaluated under the current regime. It just can’t impose any consequences based on the scores teachers receive.

State officials had already voluntarily decided to delay the most severe sanctions, such as stripping a teacher’s license, because of concerns about problems with implementation of the new system.

“Today’s ruling means that teacher evaluations will continue to move forward — period. Nothing changes,” said Robert McEntyre, spokesman for the education department. “This is simply a legal PR stunt by the labor unions after they failed to get a complete injunction. New Mexicans believe that every profession should be evaluated, and we will continue to evaluate our teachers, allowing us to praise our highly effective teachers and help those who are struggling.”

Read the order:

New Mexico judge grants preliminary injunction in teacher evaluation case