Here are some quotes lifted from a Huffington Post article by Charles Kerchner, research professor at Claremont Graduate University.
“There is little doubt that the Times is intent on publishing the names” (of LA teachers who did not show well on the value-added analysis of student test scores).” But they shouldn’t. Here’s why:”
“First, there is a difference between public officials and public employees. Public officials are fair game for just about anything, from their expense accounts to their sex lives. Traditionally, journalism has had a different relationship with public employees. We recognize that exposing rogue cops and racist firefighters falls within the purview of journalism, but we haven’t seen their performance rankings listed. That’s considered an internal personnel matter, just as it is with employees in the private sector.”
“I understand shaming mayors, school board members, even superintendents, but using a test that teachers were never told that they were to be evaluated by to publicly shame them doesn’t pass the “all the news that’s fit to print” test. There is a public interest in exposing the school district’s inadequate evaluation system. There is no public interest in shaming teachers. It’s just mean-spirited.”
“Second, the statistics are prone to error and need to be used in combination with other indicators to gain an accurate picture of teacher effectiveness. To begin with, value-added calculations are no better than the data used to calculate them: garbage in, garbage out, as statisticians say. LAUSD student data records are notoriously prone to mistakes. I have analyzed thousands LAUSD student records and remember well the task of seeing that data from one year matched the next, that students had actually taken classes from the teachers that were listed in the student record.”
“The second source of error comes from the statistical techniques used in calculating value-added measures. There is much controversy among academic statisticians about which of the many value-added calculation techniques yields the best results. As with other powerful statistical techniques, the answers one gets depends on the techniques used.”
“The propensity of value-added techniques to produce errors has been recognized for a long time, and a recent U.S. Institute for Education Sciences report concluded that the error rate could be upward of 30 percent. Moreover, rankings tend to be unstable from year to year: this year’s high ranking teacher might be more poorly ranked next year, and vice versa.”
To read the entire post, click here.