Jacqueline Bershad loved everything about the way her son's second grade teacher ran her classroom at Greenfield Elementary School in Center City Philadelphia.

She was "exactly what you would hope for in a teacher," Bershad said — warm, yet firm, giving kids just the right mix of academic rigor and fun.

"My son's teacher was the one who was at the Halloween party at night, and the picnic at night and really became involved in the community," she said. "There's some teachers who choose to do that, and some who don't."

That's why Bershad become so upset when she learned this summer that this teacher was one of the 676 being laid off by the district because of a $304 million budget shortfall.

In choosing whom to lay off, the district could not consider anything related to "merit."

Not principal evaluations. Not test scores. Not the teacher's relationship with the community.

By state code, all layoffs were based purely on seniority.

The teacher Bershad describes—who had two years experience in the district—will be replaced at Greenfield by another teacher who has been in the district longer, likely someone from one of the 23 schools that the district decided to close this year.

To some, this system represents the fairest way layoffs can be decided in a profession riddled with variables and sometimes intangible definitions of "success." To others, it's a policy that sacrifices the great teachers of tomorrow to keep the "burn-outs" of today.

As the Philadelphia school district and the teachers union negotiate a new contract to replace the one that will expire on Aug. 31, the debate is heating up. The district wants to change the rules on layoffs and seniority.

Looking for a new way

The teacher Bershad describes — who didn't want to be named in this story — was recruited specifically for Greenfield by a board composed of the principal, three teachers and a parent. This process goes by the name "site selection."

"You know as a parent I see all this time and resources and energy that have gone into creating this great person for our school," said Bershad, "and to see her laid off for reasons that have nothing to do with her performance, and then just kind of thrown into a lottery if they get the money to call people back, it just makes no sense to me. It's not using all of our resources well."

Mark Gleason agrees. He's executive director of the Philadelphia School Partnership, a nonprofit that works to increase the city's supply of high-performing schools, whether they be traditional public, charter, parochial or private.

"You often hear teachers say that test scores and students' performance on standardized tests shouldn't be the only metric in evaluating a teachers performance," Gleason said. "I would argue that seniority shouldn't be the only metric in evaluating a teacher's performance either."

He says that teacher unions have clung to the seniority rule — or "First In, Last Out" — to the detriment of public education:

"If the last person in is really one of the best educators in the building, and there's a more veteran teacher who for whatever reason is just not delivering the same kind of educational quality on a day-in-day-out basis, the principal ought to have the flexibility to say: I'm going to keep the person who's really valuable even if they're more junior."

If principals lack full autonomy in who to hire, fire or lay off, Gleason said, the Philadelphia school district cannot attract top leadership talent.

"It actually takes accountability away from management," he said, "and then you end up with principals and leaders who can't be held accountable for their results and the whole organizational culture starts to break down at that point."

The Philadelphia Federation of Teachers fervently disagrees with this assessment. It says worrying about how lay offs are executed is the wrong focus. It urges people to worry about and work to change the budget-slashing culture that leads to layoffs in the first place.

The national picture

Nationally, most teacher layoffs are still determined by seniority. Pennsylvania and New Jersey are among nine states mandate that seniority be the sole criterion. Delaware is one of 15 states that leave layoff procedures up to individual school districts.

Eleven states make "performance" the predominant factor in layoff decisions. William Hite, the Philly superintendent, would like his district to go down that path.

Trusted metrics are elusive

But here's where, according to many teachers, the situation gets sticky: How do we accurately measure performance?

Test scores?

"You can't trust the numbers," said John Carozza, an award-winning history teacher who's been in the district for 36 years.

Most of his years have been at South Philadelphia High, a school which serves students from the same neighborhood where he's lived all his life.

"Like when [students] see me [around the neighborhood] it's like, 'Mr. C., How are you? How you doing? We love you. Where you been? Are you coming back next year?' And I'm saying, 'Are you coming back next year?' You know this is the problem, 'Are you coming back?'"

Carozza retired in 2009, but returned to South Philly High this year when the principal asked him to replace another teacher who left suddenly. He prides himself on being able to teach the classes with the most unruly, under performing students.

Carozza wonders, though, if his performance would get evaluated if the focus were on test scores.

"I mean if you were to sit with me from September to June, you'd realize I've accomplished so much more than someone who's had an easier roster," said Carozza.

"For me to get a '50ish' student in the '60s,' I've done a miraculous job, and someone across the hallway who has accomplished '85s,' '90s' [with] kids who are college bound is doing a very good job most likely, but you put that person in my environment—in my classroom—and they might fall apart within a few months."

Evaluating evaluation

Like many teachers (and the Philadelphia Federation of Teachers itself), Carozza has many fears about ditching the seniority system:

Would teachers start competing to get the classes with the 'most reachable' students?

Would the fact that older teachers earn a higher salary make them bigger targets for layoffs?

In-class evaluation, as an alternative to test scores in charter teacher performance, also raises teachers' concerns.

Can administrators — who maybe haven't taught regularly in a while, or maybe have an ax to grind — be trusted to make the best decisions?

"Someone may walk in the room and give you an observation where you think you've taught the lesson of your career, and they thought it was just mediocre because not everyone was involved — and it's a natural occurrence that not everyone will be involved," said Carozza, noting that many of his students are distracted by problems they bring to class from chaotic homes and neighborhoods.

Here's something about seniority that most people miss, says Carozza: It protects those who've already proven that they can hang in and do the job.

In urban districts nationally, the numbers say that 46 percent of teachers end up quitting within five years.

"I mean there are teachers that are cut and we say, 'Oh my god, Mrs. So and So is out! She was beautiful with these children,'" Carozza says, adding that the key question is: "Can they stay around long enough with a crowd like this before taking a job maybe in the suburbs, or somewhere else where the kids are more acclimated to learning?"

Weeding out the worst

But critics of the status quo ask: Surely, there must be some older teachers who are past their prime? How can schools usher them out the door?

Even if "merit" isn't an exact science, shouldn't there be a better way to get rid of a school's most ineffective teachers?

By Pennsylvania law, all teachers must be evaluated by administrators at least once per year.

The Philly district currently evaluates teachers in a binary system. You're either "satisfactory" or "unsatisfactory." If a teacher receives two "unsatisfactory" reviews in one 10-year period, principals have the power to begin the firing process — which must go through due-process arbitration before being finalized.

"Even though they call it 'tenure,' we really don't have tenure," said Amy Roat, a teacher and union representative at Feltonville school of Arts and Science.

"I've been teaching for 20 years," she said. "If I have a bad year, I'm going to be more closely supervised. At the end of the 2nd year: still don't got it? I'm fired."

What the statistics say

So how often do these performance-based firings happen?

Currently in Philadelphia, teacher evaluations are based 100 percent on principal observation.

In the 2011-2012 year, district principals labeled 99.5 percent of their teachers as 'satisfactory.'

For the past three years on record, the school district has fired an average of 20 tenured teachers per year. That means, in a district with 7,533 tenured teachers, an average of 0.27 percent are fired for poor performance.

In total, the district has 9,100 teachers and fires an average of 39 teachers per year—marking a 0.4 percent total firing rate.

The teacher's union claims that many members who receive unsatisfactory ratings quit before being fired, but couldn't provide exact numbers.

Those firing numbers seem paltry even to Roat, even as she decries as "mythological" the notion that there's a trove of "burnt out" teachers languishing in the district.

But she said it doesn't make sense to blame the seniority-based layoff system. Instead, she said, blame some principals for lack of follow through.

"I've seen principals not bother to do the paperwork. They feel sorry for someone, or they cut them a deal," she said. "I think it makes principals feel like failures when they can't get someone to perform, but, you know, that's going to happen sometimes."

Other district teachers (who didn't want their names printed) agreed with her assessment. Some said they hadn't actually been observed by their principals in years.

Soon, though, principals' observations will mean 50 percent less.

Starting this school year, a new Pennsylvania law will base half of a teacher's evaluation on student performance— including on the state's standardized test.

Much to educators' chagrin, the test scores won't weight factors such as poverty, home-life or how many students began the year at grade level.

Moving forward

As the teachers union and the school district negotiate the terms of a new contract, seniority is one of many places where the district is seeking union concessions. It also wants $133 million worth of givebacks on salary and health benefits. (Amending the seniority rule would ultimately require a change to Pennsylvania's school code)

For parent Jacqueline Bershad, who sides with the teachers on many other issues, getting rid of seniority-based layoffs seems a fair compromise.

"Is there a potential that they may be used unfairly against some one? Yes," said Bershad, "But for anyone who has a job, we all run that risk."

Philadelphia Federation of Teachers president Jerry Jordan insists the real issue here is the lack of state funding.

Based on budget shortfalls, the district is slated to begin the 2013-2014 school year with 3,783 fewer staff members, along with dire cuts in extracurriculars, art, music and gym.

"The entire issue of layoffs should not be what we are talking about," said Jordan. "We need all of those employees that have been laid off restored."

This story was reported through a news coverage partnership between NBC10.com and NewsWorks.org