Is 'Teacher Accountability' Ready for Prime-Time?

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With a rush to implement test-based accountability before these systems have been tested experimentally, or even thought-through carefully, the Chicago district proposal is in some respects silly. What about teachers who don’t teach math or reading and so who don’t have standardized value-added scores? Or those who have not had students for a full year, or who have not been teaching the same subject for sufficient time to have value-added scores? The district proposes to evaluate these using their school-wide average value-added scores. Perhaps, with this proposal, the district is acknowledging that a teacher’s impact on a student is not only the result of her own efforts, but of the school’s entire teacher corps, working collaboratively. But if so, then individual teacher evaluation-by-test-score makes no sense (even if individual teacher data happen to be available), and student growth data should be used only to evaluate schools as a whole.

The impact of teachers’ practice on each other is apparent. Should, for example, a fifth grade teacher’s value-added score be adjusted if her students had come from a class the year before with a fourth grade teacher whose value-added score was unusually high or low? With similar students, a fifth grade teacher will have an easier (or perhaps harder) time if her students had a more effective teacher in the fourth grade. It could be easier if students had a more effective teacher the previous year, because the skills students learn in one year can give them an advantage in learning in subsequent years. Or a teacher’s job could be harder if students had a more effective teacher the previous year, because students who learn more in one year will have less room to grow in the next year. Nobody, no educational theorist or practical policy maker has an answer to this problem, and the Chicago proposal ignores this obvious source of distortion.

News reports suggest that the Chicago strike may be settled soon. The district’s latest proposal is that value-added test score data could ultimately make up 25 percent of a teacher’s evaluation, with student growth on some yet-to-be-defined “performance” tasks—writing an essay, for example—comprising another 15 percent. This is far better than what some districts around the country are attempting to do, with standardized test score data making up half of a teacher’s evaluation. The union will likely agree to something close to the district proposal, with an appeals process that is stronger than what the district has thus far proposed.

Although the Chicago teacher evaluation system will not be the worst in the country, it will still rely on methods that are not yet ready for prime time. Whether the Chicago strike slows down the rush in other places to implement a terribly flawed system, or the settlement encourages other places to try it, remains to be seen.