The teachers union and the city are heading back to court today, for the second round in an ongoing battle over the public release of teacher ratings.

Last December, a state judge ruled that that the city could release controversial teacher evaluations. Today, the union seeks to reverse that decision in Appellate Court.

The stakes are high for the city, which could use the release of teacher ratings as a key engine for galvanizing public support in favor of doing away with seniority layoffs. But the union, which wants to maintain “last in, first out” layoff rules, says that the evaluations are too inaccurate to be used for such high-stakes decisions.

The “value-added” evaluations, which grade teachers by comparing their students’ test scores to forecasted scores, were created as an internal assessment, designed to help teachers gauge their own performance. But the Department of Education announced it would release the ratings publicly after several news organizations filed Freedom of Information Law requests for them. This decision prompted a UFT lawsuit.

“FOIL requires us to release this information under law,” Department of Education spokesman Matthew Mittenthal said today.  The union, judging by its arguments at the last hearing, will argue that the reports are so subjective that they cannot be defined as “statistics,” and so do not fall under FOIL mandate. It might also refer to a 2008 agreement, in which the DOE agreed to pursue all available recourse to prevent the release of the reports.

The union could also reiterate its complaints about the accuracy of the evaluations. Last year, UFT President Michael Mulgrew held up a chart on the steps of the Supreme Court, demonstrating the alleged flaws in the evaluation’s mathematical model. At his encouragement, teachers wrote about how their grades did not accurately reflect their progress.

In December, Judge Cynthia Kern acknowledged the potential flaws in the evaluative model, but sided with the DOE when she ruled that the public’s interest in the data is justified. “There is no requirement that data be reliable for it to be disclosed,” she wrote.

The hearing is open to the public, and will take place at 2 pm at the courthouse at 27 Madison Ave.