Tuesday, August 17, 2010


The Economist


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Democracy in America

Aug 17th 2010, 17:19 by R.M. | WASHINGTON, DC -- YESTERDAY the head of the Los Angeles teachers union called for a boycott, ahem, a "massive boycott" of the Los Angeles Times over the paper's publication of articles that used student test scores to evaluate the effectiveness of teachers. Based on the test-score data, the paper found "huge disparities" among the 6,000 elementary-school teachers it evaluated, "some of whom work just down the hall from one another."

After a single year with teachers who ranked in the top 10% in effectiveness, students scored an average of 17 percentile points higher in English and 25 points higher in math than students whose teachers ranked in the bottom 10%. Students often backslid significantly in the classrooms of ineffective teachers, and thousands of students in the study had two or more ineffective teachers in a row.

A.J. Duffy, the president of United Teachers Los Angeles and caller of the boycott, scolded the Times: "You're leading people in a dangerous direction, making it seem like you can judge the quality of a teacher by...a test." He has called the Times's actions "an irresponsible, offensive intrusion" into teachers' professional lives, and a "continuing attack on our profession". Oddly, the Times notes, "Duffy attacked the reliability of standardized tests in general, but then defended the performance of his members in part by pointing to the rising graduation rates and Academic Performance Index scores at many campuses. The API is a separate statistical measure for schools which, at the elementary and middle school level, is entirely based on standardized tests."

The method of evaluation used by the Times is more complicated then simply looking at test scores. The paper performed a "value added" statistical analysis, which is a controversial measure that has been embraced by the Obama administration and some in the education community. It is meant to control for variables like poverty and family background. Roughly put, the analysis involves looking at a student's prior performance, then using that to project their future test scores. After a year or so in the classroom, it then compares the student's actual test scores with the projections, the difference being the "value" added, or subtracted, by the teacher. The Times took the results for at least 60 students and averaged them together for each teacher.

Is it a perfect form of evaluation? Certainly not. Mr Duffy is right to argue that test scores alone are not adequate for judging teacher performance. (We don't want teachers teaching to the test, after all.) And it should be noted that California's education system, in particular, is troubled by budget cuts and political infighting that make it difficult to manage and evaluate. But Mr Duffy's reaction fits with a broader resistance to more formal evaluation methods by teachers unions across the country. And that has coincided with extensive union efforts to defend teachers who are obviously failing our students. If the education-reform debate has come to seem like an attack on teachers, it is in large part because of the unions' misdirected passion and priorities.

There is no perfect way to evaluate teachers, but that is true of many jobs. (Should The Economist judge me on how much traffic this post gets? How much ad money it generates? How sharp the analysis is? Can that even be measured? How should each be weighted?) The problem is that the big teachers unions have not been credible participants in the conversation about reform, resisting efforts to incorporate test scores in the evaluation process, and fighting the consequences that must accompany bad evaluations. For its part, the Times plans to publish an online database with ratings for more than 6,000 elementary-school teachers based on test-score data. That is not fair to the teachers, who deserve a more comprehensive evaluation. But who is to blame for the absence of one?

(Photo credit: AFP)

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