For decades, teachers have entered the classroom in their early 20s and stayed in front of the blackboard for 25 years, 30 years or longer.
But that traditional model is changing.
Many educators leave teaching after just a few years -- some estimates say half leave within the first five years. But other factors are changing teacher retention, too.
In the last several years, regulations governing who can become and who can stay a teacher have tightened, especially in Tennessee, even as a generation of baby boomer teachers is retiring. Other would-be educators are entering the profession later in life, after careers as scientists, engineers or accountants. And a growing number of educators see teaching not as a career but a pit stop, as some alternative programs such as Teach for America require only a two-year commitment.
Altogether, that's a drastic shift away from a cadre of career educators who mostly were trained at teacher colleges. Officials say that means the local teaching corps is growing less experienced and less educated than in the past.
"It's got some challenges and some benefits," said Hamilton County Schools Superintendent Rick Smith, an educator for more than 30 years. "When I look at my career, there are things going on now in public education that are quite different than when I started."
In Hamilton County, the share of teachers with five years of experience or less is growing: 27.6 percent of this year's faculty are in that category, compared with 23.5 percent four years ago. Likewise, the ranks of local teachers with 11 or more years of experience are shrinking: 55.6 percent of the faculty in 2009-10 compared with 51.3 percent this year. Statewide records reflect a similar trend.
Research shows that beginning teachers grow more effective -- that is, push up student test scores -- throughout the first few years on the job, though it's hotly debated when experience levels stop affecting student achievement.
Still, many agree that inexperienced teachers often lack the classroom management skills of veteran teachers, such as knowing how to establish classroom routines, create discipline procedures, set expectations and communicate with students and parents. And that can affect student learning, because even the most talented instructors are ineffective if they can't maintain order in the classroom.
"Sometimes the thing they struggle the most with is just the day-to-day dealing with young people, whether it's discipline issues or other things," the superintendent said. "I don't think they get a good feel for that in their student-teaching experience."
This changing of the teacher workforce isn't just happening here. National research has shown that the statistical mode for a teacher's years of experience is one, meaning there are more teachers with one year of experience than any other level.
"It certainly tells us we have a lot of churn," said Sandi Jacobs, the state policy director at the National Council on Teacher Quality, a nonpartisan research and policy group. "People enter the profession and don't stay."
While alternative licensing programs like Teach for America are opening more doors to teaching than ever before, Jacobs notes that nearly all careers are becoming more transient.
"I think there's a real shift in the labor market," she said. "The idea that you're going to start and finish your career in one profession, yet alone one employer, is very different, even, than it was 20 years ago."
But what exactly is to blame for the teacher churn is up for debate.
The Washington, D.C.-based National Council on Teacher Quality advocates for educational reform. Jacobs asks if poor training programs fail to fully prepare would-be teachers. She argues for tougher entry requirements and more rigorous teacher training, saying there's no way for teacher training programs to predict who will be successful in the classroom, but that it shouldn't be a shot in the dark.
"It is clear that a significant number of teachers in the first couple of years say, 'No, this isn't for me,'" she said. "While we're never going to have a crystal ball that tells us who's going to be a great teacher, it seems we should have some better metrics for who we put in the classroom that will be effective."
Teachers union officials say drastic state policy changes are forcing good, seasoned educators out of the profession.
In just a few years, state officials have cut teacher collective bargaining rights, raised the bar for teacher tenure and linked student test scores to teacher evaluations, all much to the chagrin of teachers groups. This summer, the state's education chief pushed to open the door to teacher pay schemes that link test scores to pay and pushed to tie a teacher's license to student performance.
"What I hear across the state when I talk to teachers is that a lot of the things that are happening have made them look long and hard at retiring or leaving the profession," said Jim Wrye, lobbyist for the Tennessee Education Association. "I don't think it's any mystery that morale has suffered."
By putting more emphasis than ever before on student test results, Wrye said, the collective policy shifts make teaching more regimented and automated.
"It takes a lot of the art and the passion out of teaching for many teachers across the state," he said.
DOES EXPERIENCE MATTER?
Unions have long favored salary scales that pay teachers more for experience and education. But the exact effect that experience has on student outcomes is fuzzy.
While championing a plan to de-emphasize a teacher's educational level and years of experience in the state's minimum pay scale, Education Commissioner Kevin Huffman this summer presented research showing little relationship between student test scores and a teacher's experience level or degree attainment. Teacher groups were instantly offended by the claim, but state officials have defended their findings.
"The research in Tennessee mirrors what we see nationally, which is that years of experience and degrees earned has almost no correlation with a teacher's effectiveness," Kelli Gauthier, spokeswoman for the Tennessee Department of Education, said last week.
Teachers say common sense and anecdotal evidence suggest otherwise.
"I think it's the opposite," said Sandy Hughes, president of the Hamilton County Education Association. "Teachers become more effective over time, especially if they continue to learn."
Hughes concedes that inexperienced teachers often bring much-needed youth, excitement and passion into schools. But she said they just don't have the wisdom learned with time on the job.
"If you have a younger teaching force, you certainly have a lot of energy and enthusiasm in the classroom," Hughes said. "But with a lack of experience, people have to have more patience. Younger teachers, it's been my experience, have less patience and are less tolerant of children, for example, turning their work in late or not doing what they're supposed to do."
A teacher's level of experience doesn't always correlate to age, but it usually does, despite more fluidity in how people join the teaching ranks today.
Some people are coming to education after feeling unfulfilled in other careers, or just not finding jobs in other professions, said Stacy Stewart, Hamilton County's assistant superintendent for human resources.
But teaching jobs are getting harder to find. Thousands of teachers across the nation have been laid off in the wake of school budget cuts and the expiration of federal stimulus aid that started during the Great Recession.
Stewart said it's not uncommon for 200 to 300 people to apply for one teaching job in the lower elementary grades. And Hamilton County saw an unusually high number of retirements last year, with 100 teachers leaving.
"We've seen a lot of movement," Stewart said.
But she said turnover in and of itself isn't always a bad thing. It all depends on who's coming and who's going.
"Change can be a good thing. We want the best, most effective teachers in front of our kids," she said. "If my child were being taught by an ineffective teacher, then in that case turnover would be a good thing. What we don't want to see is our top teachers leaving the district."
Contact staff writer Kevin Hardy at firstname.lastname@example.org or 423-757-6249.