What Do Value-Added Teacher Evaluation Models Miss?
In an impassioned open letter to California's education leaders republished on the Washington Post's Answer Sheet blog, English teacher David Cohen points out eight real-life scenarios that he believes call into question the effectiveness of value-added teacher-evaluation models.
In essence, Cohen argues that real-world factors often muddle the picture that value-added systems proport to furnish. How, he wonders, would a value-added system account for the fact that he has a new principal this year, especially considering research showing that inexperienced leaders tend to lower school performance? And what about the fact that, due to scheduling changes, he now teachers more of his classes in the morningwhen sleepy teenagers are not known to be at their sharpest?
"Since half of my classes are now in the morning instead of the afternoon, please suggest a formula for the expected change in my effectiveness as measured on student tests," Cohen asks of his readers.