School systems across Northern Virginia are — grudgingly, in some cases — joining a national movement to consider student academic progress as a major factor in teacher evaluations.

On Monday, Fairfax County officials put forth a plan to base 40 percent of performance reviews on student achievement, which could mean scores on state tests, Advanced Placement exams or other measures. Other systems are finalizing plans this month.

Virginia education officials, prodded by the federal government, have required school systems to develop evaluations, effective next school year, that incorporate student growth as a key factor.

It’s a sea change in philosophy: Until now, the state’s teachers have largely been judged on how they deliver information, not on whether kids learn.

At least 17 states now base teacher evaluations largely on student performance, according to the National Council on Teacher Quality, a Washington-based advocacy group.

In the District, student progress — including standardized test scores for some teachers — counts for 50 percent in evaluations. It will count for 50 percent in all Maryland schools beginning in 2013-14.

In Virginia, under guidelines the state Education Department set in April 2011, schools must rate teachers on each of seven standards: professional knowledge, instructional planning, instructional delivery, assessment of learning, learning environment, professionalism and student academic progress.

The latter has drawn resistance in Northern Virginia from teachers groups and some school officials who say they haven’t had enough time to grapple with on-the-ground implications.

What is a good measure of progress, for example, for the approximately two-thirds of teachers whose students do not take state standardized tests? How should evaluations account for the differences — in home lives and academic preparation — that children bring with them through the classroom door?

“We’ve had some real unanswered questions,” said Steven Greenburg, president of the Fairfax County Federation of Teachers, who served on a task force that developed Fairfax’s plan.

Michael Hairston, president of the Fairfax Education Association, which also represents teachers, warned in a letter to the county School Board that the new system “may appear to be suspicious of and punitive toward all teachers,” and could discourage them from working in high-needs schools.

But Luke Chung, a Fairfax parent who served on the task force, said he is hopeful that evaluations will set higher, clearer expectations for all teachers — and that teachers will appreciate the change.

“You don’t want to be on a team where some people are coasting while you’re busting your butt,” Chung said in an interview. “Whether at a school or the Washington Redskins, that’s no good for the team.”

Until last month, most school systems operated under the assumption that they had some latitude to decide how much weight to give academic progress. But in an effort to win a waiver from burdensome parts of the federal No Child Left Behind law, state officials in May told the U.S. Education Department that school systems would be required to make student progress count for 40 percent in the ratings.

To some, the move smacked of federal interference in a local matter.

“The price of these supposed ‘waivers’ is simply too high since we do not have a valid means of equating test scores of students with performance of teachers,” Loudoun County Superintendent Edgar B. Hatrick III wrote in an e-mail.

Hatrick said he recommends student progress be given equal weight with the other six standards — a little over 14 percent.

Virginia officials have said that systems that don’t comply with the 40 percent rule this fall will have one year to submit a corrected plan.

Alexandria schools also will not comply immediately. City schools chief Morton Sherman said it’s not fair to link evaluations to student test performance as the state is introducing more-rigorous exams. “We’re setting teachers up for failure,” he said.

In most Alexandria schools, he said, student performance will account for 20 percent of teacher evaluations. It will account for 40 percent at Alexandria’s T.C. Williams High School, which in recent years has been the subject of efforts to raise student achievement.

Prince William County school officials said they have spent the past five years building, refining and using an evaluation system that includes student progress. The new state requirements will only require tweaks, they said, not an overhaul.

“The point of all of this is to make us better at what we’re doing,” said Amy White, the Prince William system’s human resources director. “A teacher’s performance is the most significant in-school factor to make a difference in student achievement.”

Virginia has developed a complicated algorithm to quantify growth in student test scores, but many school systems are choosing not to use it.

“We did not really like that model,” said Fairfax Deputy Superintendent Richard Moniuszko. “It’s a mystery. It’s like a black box.”

Fairfax is among a number of Northern Virginia systems that will instead ask teachers to set goals for their students in the fall and then gauge in the spring whether those goals have been met.

A fourth-grade teacher might aim for all students to be reading at or above grade level, as measured by a particular assessment. A gym teacher might expect all students to improve their performance on various fitness tests by 20 percent.

In Fairfax, the evaluations will lead to ratings of highly effective, effective, developing/needs improvement, and ineffective. One questions is how many “needs improvement” or “ineffective” ratings a teacher could receive before being forced into probation or dismissal. A committee of teachers and principals will resolve such issues and help implement the new system.