Friday, March 9, 2012

VAM, Blam, Thank You Ma’am

Huck/Konopacki Labor Cartoons
In a rare moment of lucidity, the New York Times published a piece this week pointing out how even the best teachers (or those with the “best” students) can end up with terrible Value Added (VAM) scores and potentially face reprisals or get fired as a result.

How is this possible?

If 85% of a teacher’s students are proficient in reading but 95% were proficient the prior year, she would earn a low VAM score because she is ostensibly doing a worse job than she did last year. Rather than adding “value” she has supposedly “lowered” the quality of education. Never mind that 85% of her students were proficient—a respectable number that should be honored, rather than punished.

Yet every year our students are different and their scores fluctuate for various reasons that have little to do with teaching, including variations in the tests themselves. Social class is the single biggest influence on test scores. So if a teacher winds up with a less affluent student population one year, test scores are likely to decline. Other nonteaching factors may come into play as well, like how the school structures the exams (e.g., all in two days, or spread out over 1-2 weeks; providing brunch for students; having teachers proctor their own students) or traumatizing social disruptions, like a tornado or earthquake.

One of the inherent problems with the current use of high stakes exams (aside from the fact that they tell us virtually nothing about the quality of teaching or what students have learned) is that they are based on moving targets. Rather than testing if students have reached a benchmark (e.g., being able to comprehend a short passage or use the Pythagorean theorem), they compare students to their peers, with some necessarily always being below the average.

Teachers at a low performing school could help their students make large gains from one year to the next, only to find that similar schools made the same progress, thus precluding them from achieving their NCLB progress goals. Likewise, there is only so far high achieving students can go, resulting in low VAM scores for their teachers when they hit this wall.

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