Students filed into Chris Cox's dim classroom at Daniel Webster Middle School in Los Angeles' Sawtelle neighborhood, took their seats and immediately began working on a language arts warmup exercise.
While Cox took roll, the eighth-graders silently worked. When they went over the answers, students raised their hands and waited to be called on.
Down the corridor, seventh-graders streamed into Brent Walmsley's classroom and took over. Some sat on table tops; others wandered around the room, pausing to grab foamy handfuls of hand sanitizer that sloshed on the floor.
As Walmsley took attendance, one boy brushed his hair, three girls sucked on lollipops while one sang Pink Dollaz's "Lap Dance," and a boy in the last row unleashed a barrage of spitballs. The day's warm-up was quickly forgotten.
Same school, same day, similar students, similar teachers -- yet profoundly different behavior.
Educators, administrators and experts say classroom management -- the ability to calmly control student behavior so learning can flourish -- can make or break a teacher's ability to be successful.
'The hardest skill'
"It is probably one of the things that's least understandable and most complex about teaching," said Randi Weingarten, president of the American Federation of Teachers. "This is the hardest skill to master."
Among the top reasons why teachers are deemed unsuccessful or leave the profession is their inability to effectively manage their classrooms, according to records and interviews.
Many California teachers who were fired and contested termination to a state panel were cited for poor classroom management, among other issues, according to a Times analysis conducted last spring.
In October, U.S. Education Secretary Arne Duncan slammed American teaching colleges for doing a "mediocre" job preparing teachers, particularly in how to manage a classroom.
Duncan's complaint is not new. Study after study confirms the importance of classroom management.
But unlike teaching calculus or chemistry, there is no single best practices method for managing a classroom. In fact, there are many, and pedagogical debates abound about what works best. Some teachers, for example, offer rewards for good behavior; others believe that creates a false motivation.
"A lot of new teachers particularly feel frustrated . . . because there isn't a recipe book that says this is what's going to work that will work all the time," said Karen Symms Gallagher, dean of the Rossier School of Education at USC.
Although there are myriad approaches, experts agree on a handful of guidelines: Teachers must be consistent in their message and consequences, lay a strong foundation of expectations early in the school year, follow through with promised punishments when children misbehave and remain dispassionate and unflappable.
Some will have an innate ability to run their classrooms, others will struggle their first years. No one can predict how they will fare until they are given the keys to their first classroom.
"No matter how much you do in teacher preparation, brand-new teachers wish you had more of it because when you're out there on your own, it's always different with your own students," said Beverly Young, an assistant vice chancellor at the California State University system, which trains 55% to 60% of the state's teachers.
In California, teachers are required to learn about classroom management in their training. The instruction varies among programs, partly because there is no one right method.
At Cal State L.A., professor John Shindler's 10-week class for those seeking to teach secondary grades covers techniques as well as underlying behavioral theory. Students must also complete 60 hours of classroom observation and 10 weeks of full-time student teaching.
Nearly all of his students said they were anxious about how they would ensure that their pupils behave.
There is widespread recognition that young teachers need support once they enter the classroom. California spends more than $100 million annually on a mentoring program for new teachers.
Last year, more than 27,000 teachers participated. And local administrators, including Webster Principal Kendra Wallace, are paying more attention to beginning teachers' needs.
When she became principal in 2004, the campus was in disarray. There were four or five fights every day. Students aimlessly wandered the campus.
Wallace made sweeping changes that have raised morale, and test scores have slowly improved. But the increased duties also prompted several veteran teachers to leave, creating vacancies that were filled by inexperienced teachers.
Wallace realized that although some had an innate ability to manage their students, many needed help.
Students must "understand first and foremost that you care about them, but that you mean what you say," she said.