Here's the dilemma: As the Gates Foundation's MET study has documented, evaluating teachers fewer than four times annually simply isn't sufficiently reliable. Anything fewer than four observations ends up producing results which are not an accurate reflection of average performance. Yet expecting that principals, even with the help of an assistant principal, can handle four observations of every teacher in a building every year may be a stretch given current school staffing patterns.
What to do? In Iowa's new plan for veteran teachers — who are now on a three-year evaluation cycle — peer reviewers will conduct observations in the two intervening years between the formal evaluations by the principal. Though Iowa's Governor Brandstad was pushing for formal evaluations by the principal every year, there are worse compromises to be had. At least this compromise provides annual feedback, if not formal evaluation, to veteran teachers.
Realities of school staffing aside, no matter who's doing the observations, one a year just doesn't cut it. There's no question that the new-found focus on teacher evaluation is posing a tremendous challenge. We're having a hard time coming up with the Chevy version of a system that seems to mandate a Cadillac — two principal evaluations and two evaluations by either trusted senior faculty in the school and/or third-party evaluators.
Washington, D.C.'s experience provides some idea of the minimum cost of a Cadillac system. Adjusting its annual price tag downwards a bit because district evaluators conduct three rather than two observations, the cost per teacher is $1,300. That's certainly not inconsequential, but pretty darn cheap in Cadillac terms.
Ruth Oyeyemi and Kate Walsh