About ‘Grading the Teachers’

The findings in this story are based on a statistical analysis of California Standardized Test scores in English and math for all students in the Los Angeles Unified School District from 2003-04 through 2009-10. The data, obtained from LAUSD under the California Public Records Act, included the names of teachers but not students.

The Times hired Richard Buddin, a senior economist at Santa Monica-based Rand Corp., to conduct a “value-added” analysis of the data. Buddin worked with The Times’ data team as an independent contractor, and Rand Corp. was not involved in Buddin’s analysis.

Under value-added, a student’s progress is measured against what would be expected based on scores from previous years. The difference is the value that a teacher added — or subtracted. Because the method compares each student to his or her own past performance, it largely controls for social and economic disparities among students. More detail on the approach can be found at https://www.latimes.com/teachers.

This analysis follows one The Times published in August rating 6,000 elementary teachers and their schools through the 2008-09 school year. In the coming weeks, The Times will publish an updated database including the rankings of individual middle school teachers and an additional year of data for both middle and elementary school teachers. Data are not available for teachers of subjects other than math or English.