Jason Song:

The Los Angeles Unified School District has declined to release to The Times the names of teachers and their scores indicating their effectiveness in raising student performance.
The nation’s second-largest school district calculated confidential “academic growth over time” ratings for about 12,000 math and English teachers last year. This fall, the district issued new ones to about 14,000 instructors that can also be viewed by their principals. The scores are based on an analysis of a student’s performance on several years of standardized tests and estimate a teacher’s role in raising or lowering student achievement.

Much more on value-added assessment, which, in Madison is based on the oft-criticized WKCE.