In response to the May 14 article “In doubt: Using student test scores to measure teacher quality,” I offer the following observation.

If you designed a controlled experiment (uncontrolled experiments being largely worthless) in which two teachers of roughly the same experience and education taught the same material, for a discrete period of time, to roughly similar students who were then tested under like conditions, you might be able to figure out who was the better teacher of that material for those kids at that time.

But real school is not a controlled experiment. It is a 12-year-long experience, one in which boys and girls growing at uneven rates experience school with hundreds of different kids, dozens of teachers and perhaps two or even three families.

They develop different skills and interests and respond better or worse to various types of teachers teaching a wide variety of subjects employing all manner of pedagogy.

Teaching “Go, Dog. Go!” is not the same as teaching “Hamlet.” Teaching adding and subtracting is not the same as teaching change over time. Collecting leaves is not the same as memorizing the formula for chlorophyll.

There is no fair or sensible way to compare or account for the variation in kids’ test scores. Some students do very well on standardized testing; others do not.

We know that different styles of teaching are helpful in meeting the needs of various kinds of learners. Some kids do better with some teachers than with others. Think of your own experience.

You just can’t account for the influence of teachers. The whole enterprise of education is overdetermined. Evaluating and/or paying teachers on the basis of student test scores is unfair and unworkable. We should not do it in Maine.

Chris Queally

retired English department chair, Thornton Academy

Scarborough