Value-added assessment: Theory vs practice
The following was written by Matthew Di Carlo, senior fellow at the non-profit Albert Shanker Institute, located in Washington, D.C. This post originally appeared on the institute’s blog. By Matthew Di Carlo A few weeks ago, the National Education Policy Center (NEPC) released a review of last year’s Los Angeles Times (LAT) value-added analysis – with a specific focus on the technical report upon which the paper’s articles were based (done by RAND’s Richard Buddin). In line with prior research, the critique’s authors – Derek Briggs and Ben Domingue – redid the LAT analysis, and found that teachers’ scores vary widely, but that the LAT estimates would be different under different model specifications; are error-prone; and conceal systematic bias from non-random classroom assignments. They were also, for reasons yet unknown, unable to replicate the results. Since then, the Times has issued two responses. The first was a quickly published article,
