Aimee Horowitz, center, visits a 12th grade English class at Boys and Girls High School, Tuesday, March 10, 2015, in the Brooklyn borough of New York. Mayor Bill de Blasio and Schools Chancellor Carmen Fariña announced that Horowitz will become the new Renewal Schools leader, responsible for bringing progress to 94 struggling city schools. (AP Photo/Bebeto Matthews)

This story has been updated.

A new analysis of New York City school data shows that teachers who scored low in the city’s evaluation system are concentrated in struggling schools that tend to serve poor and minority students, while teachers with strong ratings are most likely to be found in schools where students test well and tend to be white and Asian.

The analysis, by Families for Excellent Schools, an advocacy group that has been campaigning to expand public charter schools, shows a strong correlation between teacher quality — as measured by the city’s system — and how students perform on standardized tests.

“The data shows just how tightly linked student achievement is to teacher quality, and helps lay bare the fault lines of educational inequality in New York City’s schools: race and poverty are the most critical factors for whether you have good teachers in the classroom,” said Khan Shoieb, a spokesman for Families for Excellent Schools.

The organization looked at 2013-2014 ratings for 20,167 public school teachers at 553 elementary and middle schools in New York City, about one-third of the public school system.

The group found that as teacher quality, as defined by the city’s ratings system, increases, students are more proficient in English and math and are less likely to be poor, black and Hispanic. There were outliers – examples of highly rated teachers working in schools where students demonstrated low proficiency – but those exceptions were relatively few.

It is perhaps unsurprising that teachers at low-performing schools have low job performance ratings, since 40 percent of teacher evaluations in New York in 2013-2014 were based on student test scores. (State lawmakers have since made a controversial change promoted by Gov. Andrew Cuomo (D) that requires 50 percent of a teacher’s rating to be based on test scores, starting with the 2015-2016 school year).

“When we attempt to draw a straight line between the effort of a teacher and the success of her students, based solely about test scores and ignoring all other factors, here’s what happens: Teachers in high poverty, racially segregated schools where students are more likely to perform poorly on exams are then viewed as ‘poorer quality’ teachers,” said Randi Weingarten, president of the American Federation of Teachers. “At the same time, teachers in middle class, racially integrated or predominately white schools where students are more likely to perform well on exams are designated ‘higher quality’ teachers.”

“New York City’s students deserve better than straw man arguments,” Weingarten said.

She pointed to a recent national poll that found Americans overwhelmingly think there is too much emphasis on standardized testing in public schools and that test scores are not the best way to judge schools, teachers or students.

[U.S. schools are too focused on standardized tests, poll finds.]

“If the latest PDK/Gallup poll told us anything, it’s that American parents want less emphasis on testing and more emphasis on improving curriculum, boosting funding, lowering class size and supporting teachers,” Weingarten said.

Shoieb, of Families for Excellent Schools, pointed out that New York’s teacher evaluation model is designed to correct for demographic differences, so that a teacher in an impoverished East Harlem school is not compared with a teacher at an affluent Upper East Side school. Shoieb argued that the best teachers are attracted to high-performing schools because the work is easier and the school climate is better, something the organization says is displayed in the new data.

“The best teachers are concentrated in the best areas and we all know why that is,” he said. “These are the easiest schools to teach in, where they don’t have to deal with the toxic stress of poverty, they don’t have to deal with kids who are hungry. Instead, they get the kids who are easier to teach.”

“At the same time, we know that the teacher quality score means something and we think this is certainly a call to action,” Shoieb said, adding that offering bonuses to highly rated teachers who choose to work in troubled schools is one solution.

He said another solution is to expand high-performing charter schools, an issue that has led to repeated clashes between Mayor Bill de Blasio and Families for Excellent Schools. Charter schools are publicly funded but privately run and are largely not unionized.

Wiley Novell, a spokesman for de Blasio, said the mayor and New York Public Schools Chancellor Carmen Farina are working to raise teacher quality, particularly at struggling schools.

“Mayor de Blasio and Chancellor Farina don’t accept the status quo,” Novell said. “That’s why they’ve expanded teacher training. It’s why the city required every superintendent and all faculty at our longest-struggling schools to reapply for their jobs. It’s why we’re investing hundreds of millions of dollars in low-performing schools that for years were abandoned and left without the resources they needed. Those are solutions at a scale that don’t leave any kids behind.”

Increasingly, public school systems around the country are divided by race and class, with poor children — who are often black and Hispanic — attending school alongside other poor children while their wealthier counterparts attend different schools.

National data shows that inexperienced teachers are more likely to be found in high-poverty schools, where they also are more likely to be uncertified, working under emergency certification or teaching subjects outside their field, than teachers at schools that serve more advantaged students.

No Child Left Behind, the 2002 main federal education law, required states to take steps to ensure that minority students and those from poor families are not taught by unqualified teachers at higher rates than their more advantaged peers. But the federal government has largely not enforced that provision. The U.S. Department of Education did require every state and the District of Columbia to file a plan for how they intended to correct any imbalances, but that has been the extent of action.