In his post, “Getting Value-Added Right,” Robert raises excellent questions, and his restaurant metaphor is apt. The value-added growth model, as Dan Willingham notes in the comments section and his post on the Britannica Blog, is not ready for prime time. There are too many intervening variables to hold teachers solely accountable for the test-score growth of every student. Given high rates of mobility, there is a large fluctuation in the student population in schools. As Thomas J. Kane and Douglas O. Staiger point out in one of their papers, their inherent volatility make test scores a poor basis for an accountability system.
The imprecision of test score measures arises from two sources. The first is sampling variation, which is a particularly striking problem in elementary schools. With the average elementary school containing only sixty-eight students per grade level, the amount of variation stemming from the idiosyncrasies of the particular sample of students being tested is often large relative to the total amount of variation observed between schools. The second arises from one-time factors that are not sensitive to the size of the sample; for example, a dog barking in the playground on the day of the test, a severe flu season, a disruptive student in a class, or favorable chemistry between a group of students and their teacher. Both small samples and other one-time factors can add considerable volatility to test score measures.
There are many, many reasons why one-year changes in scores are not reliable. There are many reasons why it is hard to give credit or blame for students’ test score gains and losses from year to year. Until we have better tests and have ironed out many of the confounding variables, it is unfair to make credible inferences about teacher performance from test scores, let alone use such data to dispense rewards and punishments.
There is another reason to worry about value-added growth models that determine a teacher’s fate and compensation. If we turn teaching into an activity whose sole purpose is to produce gains on tests that we know are mainly low-level and dumbed-down, we will not make education better. We may succeed in destroying it altogether. We better find ways to emphasize the quality of curriculum (think Core Knowledge) and to de-emphasize the number of times that kids are asked to check off a box on standardized tests in the course of a month. Or our education system will be far worse than ever.
Diane blogs on education at Bridging Differences — ed.
Not content with making 50 the new zero, one North Carolina school district is considering imposing a lowest possible grade for tests or assignments of 61.
Proponents of eliminating zeroes as grades for work not submitted point out that A, B, C, and D letter grades are typically signify increments of ten — an A is 100 to 91; B is 90 to 81, etc. — but there is a 60-point spread between D and F, which makes it mathematically impossible for some failing students to ever catch up.
“There is little or no evidence that repeated failure makes people more responsible,” Sherri Martin the Chapel Hill-Carrboro district’s director of high school programming said at a Board of Education meeting last week. “The threat of a low grade is more likely to motivate high-achieving students than low-achieving students.”
Many parents and teachers disagree. “The system for years had talked about raising expectations for all children in the district, and I don’t feel that demonstrates raised expectations for everybody,” said Beth Ann Ghio, whose son is an East Chapel Hill High junior. “I don’t think that’s fair for children who actually submit the work — even if it’s not passing quality — that they receive the same grade as a student who doesn’t submit anything.”
Writer and parent Maura J. Casey complains in the New York Times (So Is That Like An A?) about report cards in Hartford, Connecticut. The reports—clearly not cards—are up to seven pages long and grade a child on how he or she “establishes and maintains a healthy lifestyle by avoiding risk-taking behavior” and 57 other academic, social and behavioral criteria. In music class, for example, students are being graded on how they make “connections between music and other disciplines through evaluation and analysis of compositions and performances.”
It’s no mere rant. Casey points out that the academic measurements, which are designed to grade areas of student performance that are also measured on state standardized tests, seem more likely to confuse than illuminate. “I confess that as a parent, I’ve always focused on the basics. I want my children to be curious, enjoy learning, to read for pleasure, to be polite, to do their homework and to try not to hate school. If my kids got A’s or B’s, I got a pretty good sense that they were mastering the necessary skills. If they did much worse, I knew that it was time to call their teachers,” Casey writes.
In cities like Hartford, where many students come from non-English speaking homes, Casey points out that educational jargon like “uses numeracy and literacy skills to describe, analyze and present scientific content, data and ideas” seems destined to confuse, not clarify. “If report cards are weighed down with educational jargon that even native English speakers have to struggle to understand, ” she concludes, “it is fair to ask who the administrators are really reporting to: students and their families or the educational bureaucracy?”
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