Los Angeles Unified has until Dec. 4 to implement a system for including student test scores in teacher evaluations, under an agreement negotiated Tuesday by attorneys for the district, its unions and a parent advocacy group.

The deadline was set as Los Angeles County Superior Court Judge James Chalfant pushed the district to obey his order to comply with the Stull Act, the 41-year-old law which mandates that student performance be used to help gauge teacher success. After a legal squabble in the courtroom, Chalfant sent attorneys into the hallway to hammer out a timeline for complying with a ruling he issued last month.

There will be a "gut-check" on Sept. 4, to make sure the district is on track toward a final Dec. 4 deadline, said Bill Lucia, executive director of EdVoice, the advocacy group that filed suit challenging the district's teacher evaluations. Lucia called the timeline realistic, and said it ensures that a system will be in place next spring for ensuring that students are in a classroom with an effective teacher.

Jesus Quinonez, an attorney for United Teachers Los Angeles, said the union and district have a negotiating session scheduled for Wednesday as they work to hammer out the details of the evaluation system.