LA Times Does a Statistical Analysis of Student Test Scores to Identify Good and Bad Teachers

Now that is investigative journalism. Of course the unions hate it. God forbid they be judged by how their students do. Read the whole article, it's worth it:

In Los Angeles and across the country, education officials have long known of the often huge disparities among teachers. They've seen the indelible effects, for good and ill, on children. But rather than analyze and address these disparities, they have opted mostly to ignore them.

Most districts act as though one teacher is about as good as another. As a result, the most effective teachers often go unrecognized, the keys to their success rarely studied. Ineffective teachers often face no consequences and get no extra help.

Which teacher a child gets is usually an accident of fate, in which the progress of some students is hindered while others just steps away thrive.

Though the government spends billions of dollars every year on education, relatively little of the money has gone to figuring out which teachers are effective and why.

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• Highly effective teachers routinely propel students from below grade level to advanced in a single year. There is a substantial gap at year's end between students whose teachers were in the top 10% in effectiveness and the bottom 10%. The fortunate students ranked 17 percentile points higher in English and 25 points higher in math.

• Some students landed in the classrooms of the poorest-performing instructors year after year — a potentially devastating setback that the district could have avoided. Over the period analyzed, more than 8,000 students got such a math or English teacher at least twice in a row.

• Contrary to popular belief, the best teachers were not concentrated in schools in the most affluent neighborhoods, nor were the weakest instructors bunched in poor areas. Rather, these teachers were scattered throughout the district. The quality of instruction typically varied far more within a school than between schools.

• Although many parents fixate on picking the right school for their child, it matters far more which teacher the child gets. Teachers had three times as much influence on students' academic development as the school they attend. Yet parents have no access to objective information about individual instructors, and they often have little say in which teacher their child gets.

• Many of the factors commonly assumed to be important to teachers' effectiveness were not. Although teachers are paid more for experience, education and training, none of this had much bearing on whether they improved their students' performance.