SALEM — Oregon unveiled new ratings for nearly every school in the state Friday, part of a new evaluation system that replaces ratings under the No Child Left Behind federal education law.

SALEM — Oregon unveiled new ratings for nearly every school in the state Friday, part of a new evaluation system that replaces ratings under the No Child Left Behind federal education law.

The new ratings are based largely on how much students improve their reading and math skills from year to year. Under the old system, schools were measured based on whether their students passed or failed standardized tests.

The ratings show Oregon's best-performing schools are mainly those that serve neighborhoods with well-off, well-educated parents and residents who value good schools. As a group, elementary schools tended to score better than middle schools, which did better than high schools.

Among schools that receive federal anti-poverty money, the new evaluation system lists 35 low-performing "priority schools" that will have to figure out what they're doing wrong and launch an improvement effort by next summer, The Oregonian reported. Another 60 high-poverty schools that performed slightly better were labeled "focus schools."

Ashland's John Muir wilderness school was one of the 27 high-poverty schools recognized for high performance, the Mail Tribune reported.

On the flip side, 27 schools that get federal poverty funding are named top-performing "model schools," and their techniques will be studied and shared. The identification of high-performing schools is new for Oregon.

"These are the schools that all schools can emulate," said Jon Wiens, Oregon's school accountability specialist.

Oregon won the right to develop its own system for rating schools last month, when the Obama administration approved an application to drop some provisions of No Child Left Behind.

The new system uses a sophisticated measure of past test scores to compare each student's growth on state reading and math tests with that of students with the same previous performance. It is designed to avoid rewarding schools simply for enrolling bright, high-scoring students; they'll be required to show they're pushing their students ahead.

A major focus of the new rating system is to identify a relatively small number of schools with the most profound problems, rather than list hundreds in great need of improvement, as No Child Left Behind rules likely would have done this year.

Identifying too many schools diluted the support and feedback each could get, and it called into question whether all were seriously ineffective, state officials said.

Picking the few with the deepest, most persistent problems "will allow us to both understand what is happening in these schools and districts and then go to the pain points of their performance," said Rudy Crew, the state's new chief education officer.

"Our role is going to be to go in and be fairly exacting," Crew said. "Where necessary, we will have to be far more restrictive and far more controlling than maybe people might like."

Most Oregon schools aren't labeled priority, focus or model schools. The evaluation system measures achievement on a scale of one to five, with higher numbers denoting better schools.