It’s not obvious that this is best way to do things, though. It constrains the principal’s judgment and discretion: she may believe a component of the evaluation to be misleading, for instance, but can do nothing to adjust it.Some may argue that a mechanical model provides needed principal-proofing, but there is research suggesting that principals typically make smart personnel decisions. Given their accountability for school performance, it’s worth experimenting with less rigid systems that engender rather than diminish principal autonomy.
However, it is certainly possible that recent evaluation systems have made teaching less appealing in some circumstances — high-poverty schools, for instance, which already often struggle to recruit and retain teachers in part because of poor working conditions. Teachers in these schools are generally at greater risk of being identified as low-performing, and potentially fired, under new evaluation systems. Making the teaching profession riskier, in perception or reality, may make it less appealing.
Some lessons may be drawn from Washington, D.C., which has been among the most aggressive in identifying and dismissing struggling teachers in disadvantaged schools. Researchers have found that the district has been able to replace poor performers with better ones, perhaps in part because of high salaries differentiated by performance and school population. D.C. public schools have also developed performance screens when hiring that seem to be helpful in determining who will be effective in the classroom.Districts with aggressive evaluation systems that generate more teacher dismissals should pay particular attention to this issue, and ought to consider pairing evaluation reform with higher salaries or other efforts to make the job more appealing.
1. A handful of states use a ‘matrix’ model in which scores on two dimensions are combined to create a summative rating. This is essentially a cruder version of a percentage-based system.