The Los Angeles teachers union president said Sunday he was organizing a "massive boycott" of The Times after the newspaper began publishing a series of articles that uses student test scores to estimate the effectiveness of district teachers.
"You're leading people in a dangerous direction, making it seem like you can judge the quality of a teacher by ... a test," said A.J. Duffy, president of United Teachers Los Angeles, which has more than 40,000 members.
Duffy said he would urge other labor groups to ask their members to cancel their subscriptions.
Based on test score data covering seven years, The Times analyzed the effects of more than 6,000 elementary school teachers on their students' learning. Among other things, it found huge disparities among teachers, 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.
The district has had the ability to analyze the differences among teachers for years but decided not to do so, in large part because of anticipated union resistance, The Times found.
The newspaper plans to publish an online database with ratings for the more than 6,000 elementary school instructors later this month.
After learning of the analysis and the database last week, union leaders began making automated calls to teachers objecting to publication. In the Friday evening call, Duffy said the database was "an irresponsible, offensive intrusion into your professional life that will do nothing to improve student learning."
"Our attorneys are looking into the legalities of this database," he said in the recorded message. "This is part of the continuing attack on our profession, and we must continue to fight back on all fronts."
On Sunday, Duffy declined to talk about any legal action or other protests besides a boycott. "I'll keep that to myself," he said.
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.
Last week, the union president told reporters that he thought test scores could be useful as feedback for teachers but should not be used for evaluation.
The Times analysis used a "value added" statistical analysis of math and English scores from the school district -- the nation's second largest -- to estimate the effectiveness of third- through fifth-grade teachers.
The analysis compared each student's prior performance to project his or her future test scores. The difference between the projection and the student's actual performance was the "value" the teacher added or subtracted. The results were averaged over at least 60 students per teacher to ensure statistical reliability.
The method, although controversial among some teachers and policy experts, has been embraced by the Obama administration and other education leaders.
One advantage is that it largely controls for outside influences like poverty and family background. Other districts are also using it as part of evaluations or the basis for merit pay programs, moves that have generated fierce resistance from some teachers unions and skepticism from some experts.
The paper received nearly 500 reader comments on Sunday's article. And nearly 300 teachers submitted e-mails to The Times to ask for their own value-added scores.
Many teachers were highly critical of The Times' decision to publish educators' names and their results. One teacher called it "a disgrace." Others, however, said it would foster a healthy discussion.
"Open debate and full disclosure will force those in charge to do something rather than play defense," said Gary Hubbert of Palm Springs in an e-mail to reporters.
Supt. Ramon C. Cortines acknowledged last week that the district had not made good use of its own data, which he called the best in the country. He endorsed moving forward with value-added as one measure of teacher effectiveness.
Later in the week, Cortines asked state lawmakers to push through reforms to allow the district to make decisions based on teachers' effectiveness, not just seniority.
John Deasy, the district's recently appointed deputy superintendent and considered a likely candidate to replace Cortines, called The Times approach "careful" and said he hopes to include value-added as a component of teacher evaluations. He said, though, that the majority of an evaluation should be based on teacher observation and other factors.
The current evaluation system consists of brief, preannounced classroom visits. Nearly all teachers receive passing grades, The Times found last year.
Deasy said teacher effectiveness is "paramount; the absolute center of how we're going to improve student achievement in this district."
The Times will publish the database later this month after teachers have been given a chance to view and comment on their scores. The deadline for teachers to comment for the initial posting of the database is Thursday at noon.