For all the education research and policy types out there, there’s a pretty good food fight taking place between the National Education Policy Center at the University of Colorado and the Los Angeles Times.
It concerns value-added modeling of teacher effectiveness – in particular, the Times project last summer that used test-score data and a value-added formula to give an effectiveness rating to 6,000 elementary-school teachers in the Los Angeles Unified School Districts.
The Times project, which was highly controversial and sent the LA teachers’ union into a frenzy, was based on a value-added analysis by Richard Buddin, a researcher with Rand Corp. The paper put LA teachers into one of five “effectiveness” categories based on their students’ test-score improvement and published a database of the teacher ratings on its website.
UC researchers Derek Briggs and Ben Domingue re-analyzed what they believed to be the same data. First they conducted a “sensitivity analysis,” which produced results that cast doubt on whether Buddin’s approach measured teacher effectiveness, not other factors that influence student achievement.
Next, they ran the data using a slightly different, but arguably valid, value-added model. The result was that about half the LA teachers ended up with a different effectiveness rating, calling into question the validity of the entire exercise.
“This study makes it clear that the LA Times and its research team have done a disservice to the teachers, students, and parents of Los Angeles,” said NEPC director Kevin Welner. “The Times owes its community a better accounting for its decision to publish the names and rankings of individual teachers when it knew or should have known that those rankings were based on a questionable analysis.”
The Times reported on the NEPC study but claimed that it “confirms the broad conclusions of a Times analysis of teacher effectiveness in the Los Angeles Unified School District” because it showed that the effectiveness of teachers varies widely and can be reasonably estimated. Continue reading