Suppose a swimming instructor told his 10-year-old students to swim the length of the pool to demonstrate what he'd taught them, and half of them nearly drowned? Would it be reasonable to make a judgment about his teaching ability?
Or suppose nearly all the 10-year-old students in a particular clarinet class learned to play five or six pieces well in a semester? Would it be reasonable to consider their achievement when deciding whether to rehire the music teacher?
These questions answer themselves. Only an idiot would overlook student performance, be it dismal or outstanding.
However, suppose test results indicated that most students in a particular class don't have a clue about how to multiply with fractions, or master other material in the curriculum? Should that be considered when the math teacher comes up for tenure?
Whoops, the obvious answer is wrong. That's because public education lives in an upside-down universe where student outcomes are not allowed to be connected to teaching.
And so we have the battle lines drawn in the battle to assess teacher performance. As EIA pointed out, the author's credentials cannot be easily dismissed:
Mr. Merrow, a former teacher in high school, college and federal prison, is education correspondent for the "NewsHour with Jim Lehrer" and president of Learning Matters, Inc.
So, how do we address his points? Hidden in his essay is the answer:
Of course, not every kid comes to class equally able to complete the day's assignment. Some are new immigrants, others are gifted, and still others might have a learning disability. These factors affect test scores as much as or more than who is teaching.
Still, students at whatever level of performance can also be evaluated on how much they've improved over a given period of time.
Tennessee pioneered "value-added assessment", which allows schools to determine how much value an individual teacher or school adds to student performance over time. A good explanation of how such an assessment is done can be found here.
I certainly don't think it's fair to place the power over a person's employment into the hands of students. However, if we can determine through scientific analysis that a particular teacher consistently underperforms, that their students do not grow a year's worth during a school year, then targeting additional effort to help that teacher improve his or her pedagogy would be a wise use of resources.
I understand the arguments against many of the methods proposed to evaluate teachers using student test scores. However, I don't see good arguments against a value-added system.