Teacher Evaluations: Presumption of Incompetence

[Modern School]

In San Francisco Unified (SFUSD) last year, 40 out of 1,924 teachers (2%) received bad reviews. Over the past five years, an average of 2.7% teachers received marks of “unsatisfactory” or “needs improvement.” In nearby San Jose and Oakland, only around 1% of teachers received poor ratings.


The Ed Deformers love to hold up numbers like these as proof that the teacher evaluation system is broken. What the Ed Deformers are actually demonstrating by such abuse of data is their own ignorance and incompetence. Low numbers of unsatisfactory reviews does not prove that the evaluation system is broken any more than high temperatures indicate a broken thermometer. These results could mean that there are actually very few bad teachers. There is no reason to assume that there must be more bad teachers than are being caught by the current system or that there is necessarily a bell curve of teacher aptitude.

To read the complete article, please go to http://modeducation.blogspot.com/2011/01/teacher-evaluations-presumption-of.html

[ElboRuum]

1. However...

Absence of evidence is not evidence of absence either. In any occupation open to anyone willing to obtain the training/credentials to do that job, the bell curve does tend to apply. A few stars, a few losers, and a whole continuum in between. Is 2.7 percent a normal number of unsatisfactory teachers? Only if our standards are placed more than two standard deviations below the mean. If the distribution applies to teachers, and you've supplied no evidence to suggest that it does not, then what is satisfactory allows the bulk of teachers that are below average to keep their jobs.

The use of satisfactory versus unsatisfactory bothers me as well, because it is unclear what is meant. Does satisfactory mean good? Or does it mean doing at least the minimum required according to the standards presented? I am certainly willing to entertain the idea that the teaching profession is populated in its near entirety with competent, effective instructors, but the results defy this assertion and indicate that we look elsewhere other than 'teacher, therefore competent' for an explanation for that number.

Other assertions which strike me as less than convincing:

"Excellent Teaching Does Not Always Produce Excellent Students"

Well of course. It NEVER does. You can't produce an excellent student by force of will or excellence of methods without a great deal of assistance from the students themselves. However, the measure of excellence should not be whether the student is a better student in the abstract for having had a particular teacher, rather, whether the teacher was effective in conveying an understanding of the course material in spite of the student's abilities or attitudes within fair reason. Excellent teachers are the ones who have strategies for reaching most students, and they get generally better results on the whole than those who do not.

"Low numbers of unsatisfactory reviews does not prove that the evaluation system is broken any more than high temperatures indicate a broken thermometer."

No, but does a high temperature reading when it's damn cold at least indicate the possibility that the thermometer is broken? Does the fact that students appear to be leaving their scholastic experience with less and less intellectual skill at least indicate that 2.7% isn't a sign that we have only a handful of bad teachers, and that the bar as to what is passing as satisfactory might be too low?

The best point you made was about the evaluations themselves, although I did think the qualifier 'may', italicized in an obvious way, seemed an obligatory concession.

"Another problem is that administrators are stretched thin with all their other responsibilities, which means that they seldom have the time for many classroom observations of their teachers or to give adequate attention to teacher portfolios. This may result in some teachers receiving satisfactory evaluations when in fact they actually need improvement."

This puts a fine point on a specific issue: if we really want to improve the schools, and we are going to formally evaluate teachers, then one of the greatest priorities of the administrators should be the role of evaluator. If what you say is the case, and there is no reason to believe that it isn't, then it will result in satisfactory evaluations where there should not be. No 'may' about it.