Principal Pamela Price Haynes has worked at P.S. 161 in Harlem for 28 years. Every morning and afternoon, she can see how charter schools have changed the face of the neighborhood when she watches the crowds of students wearing gray, navy or khaki uniforms coming and going to their schools.

But Price has another observation about the impact of charters.

“People who work in public education, public schools, feel that we are the dumping ground,” she said.

This blunt view is shared by many teachers and principals in the city’s district schools. They’re frustrated that charter schools – which are also public but have more autonomy – have higher than average test scores, which they attribute to strict rules that make it possible to push out students with behavioral problems and low grades.

P.S. 161 Principal Pamela Price Haynes

This perception has shadowed the charters for years, even though studies have found they make academic gains with the same type of students who attend traditional public schools and kids who applied but didn’t get into charters.

But there’s been little research on the students who leave charters. WNYC obtained three years’ worth of discharge data from the city’s Department of Education. We found no exodus from the charters. In fact, the charters had lower attrition rates, on average, than the regular public schools. Attrition in charter elementary schools for 2010-11 was 10.8 percent citywide, compared to 14.3 percent in district schools. Middle school attrition was lower in both categories and more comparable, at around 10 percent.

What we found in the three districts of Harlem, however, are several charters and district schools where annual turnover can be as high as one out of five students. There are lots of possible reasons. Poverty is one. Experts say high attrition is common in poor communities because families move around often. But the churn in Harlem also seems to be related to the booming market of school choice.

At P.S. 161, which has more than 900 students in grades K through eight, the attrition rate for elementary students was 16 percent in 2010-11, according to the Department of Education. Some kids leave for charters but others transfer in from charters. In one fifth grade class of 25 students, four hands shot up when a teacher asked if any one ever attended a city charter school. A boy and a girl who went to Harlem Link charter both recall lots of rules.

“I was being bad, my Mommy had to come up to the school,” said the girl. “They kept on saying I was playing around too much and couldn’t stop talking.”

“I would play on the rug and then they would say I have to go to my seat and put my head down,” said the boy.

Harlem Link said these students were not kicked out and their families agreed. The girl’s mother, who asked that we not use their names, said her child did well at Harlem Link. But she found the rules “petty,” noting that she was called at work because her daughter’s belt wasn’t all black, as required.

Harlem Link is familiar with complaints about its rules. The school, which shares a public school building on West 112th Street with a few other schools, takes its uniform policy very seriously. Teachers keep daily charts of student behavior and families sign contracts pledging to review these reports. Children are also reminded to keep their voices low. Infractions can earn a child deductions, which can add up to detentions. These policies create a culture of high standards, said principal Steve Evangelista, who presides over breakfast and calls everyone to order with the gentle sound of a chime.

“By this time I should see every scholar tracking me,” he announced one morning as the children passed their trays to garbage cans and prepared line up for first period. Evangelista spotted three boys who continued talking and pulled them aside. They would have to skip recess as punishment.

Photos: Inside P.S. 161 and Harlem Link Charter School

Charles Taylor, whose son was among the three, said he appreciates the elementary school’s no nonsense approach.

“It’s important for children to learn that they must conduct themselves in an orderly and respectful fashion in a school environment,” he said. “That’s really a tough lesson for kids to learn but it’s a necessary one.”

Another parent, Angela Dupree, agreed and said she’s grateful for options like Harlem Link.

“I am very happy because it gives us the opportunity to shop around,” she said, noting that another daughter graduated Harlem Link last year and is now in junior high. “Like, I couldn’t believe some of the schools that she could possibly get into and she actually got accepted to the majority of junior high schools she wanted.”

But Dupree isn’t done shopping. She is thinking of moving her younger daughter out of Harlem Link, because she had to repeat kindergarten. She also thinks the uniform policy is too strict.

“I said that to my husband last night, I’m going to have to start choosing a school just like I choose what type of sneakers I should buy,” she said.

Evangelista acknowledges the school has lost some students because their families didn’t like its culture, and preferred to go elsewhere. There are now 25 charter schools in Harlem, alone.

“It’s a community where there has never been this kind of choice and you’re talking about unprecedented choice for any community in the United States,” he said.

Margaret Ryan and Steve Evangelista co-founded Harlem Link charter school in 2005.

Evangelista believes this level of choice has contributed to the school’s attrition rate, which was over 20 percent in recent years. That’s higher than the citywide average but similar to regular schools in parts of Harlem.

“Last year we had a fourth grader who was here for kindergarten, first grade, gone for second and third grade, came back for fourth and left after fourth because of dissatisfaction,” he said. “Nothing’s never good enough. Which is a great attitude but the trauma of moving a child is sometimes lost on families.”

Experts agree there’s a downside to all this mobility.

“It creates discontinuity in students’ schooling, and their exposure to curriculum and a steady stream of continuous instruction and continuity of care in the schools,” said James Kemple, executive director for the Research Alliance for New York City Schools at New York University.

While there’s no hard evidence that children with poor grades and attention problems are being counseled out of charters, Evangelista concedes there’s a grain of truth to the perception that kids leave charters because they’re more demanding. He and his wife, Margaret Ryan, are former New York City public school teachers who opened their school in 2005 so they could focus on good teaching. The school struggled academically for a few years but improved after they tightened some of the rules. At Harlem Link, a child can be held back a year for missing more than 15 days of school.

“The fact is [the fact is the fact] that a parent can leave Harlem Link if we’re pushing back that their child has already missed 10 days by October,” said Ryan. “They can can go to neighboring zoned school and not hear pushback on attendance. The same with uniforms.”

Ryan and Evangelista said their school works with families to explain its policies and keep pupils on track, and that fewer students are leaving now when they’re held back a grade.

Still, grade retention is one reason why several teachers at the district schools in Harlem say they receive students from charters. A supervisor at a Harlem middle school who did not want to be identified said most of these students are low-performing, and “kids seem to get the message: you can’t handle this go to a public school.”

The teachers union also notes that charter schools don’t always replace students who leave mid-year, which means they’re less likely to receive new students who might be far behind academically or struggling in other ways. This is one commonly held theory why some of the charters have higher test scores. Charters also tend to have longer school days, which some families love but others find exhausting.

Teachers and principals at district schools also believe some charters do have different populations. A a report by the New York City Charter School Center found charters serve a smaller percentage of Hispanic students, overall, than the city’s district schools and far fewer students who are still learning English (less than 6 percent in charters, compared to 15 percent citywide). This could have something to do with where the charters are located. They also serve fewer of the neediest special education pupils.

At P.S. 161, which has many Hispanic students, Principal Price notes that nearly a third of her pupils are still learning English. The charters in Harlem don’t have such high concentrations.

But in other ways, P.S. 161 doesn’t look all that different from a charter. It’s putting more focus this year on student behavior in hallways and classrooms. Students are also given yellow warning cards for misbehavior – just as they are in Harlem Link. And while the school has long had a uniform policy, it’s doing more this year to encourage its students to wear them.

Price said these rules were not established in response to the competition from charters. Instead, she noted that these management techniques are common at all kinds of schools. She said she wanted to establish a more respectful environment now that her school has expanded to include middle grades. But there’s a different emphasis at P.S. 161 than in a charter, said assistant principal Leslie Ellman.

“Classes with 100 percent uniforms are being celebrated on the loudspeaker,” she explained. “It’s a really different approach to focus on the positive rather than the negative. Instead of coming up with how many ways are we going to punish everybody for not following the rule, it’s like how many ways can we celebrate everyone who is so everyone wants to.”

Ellman and her colleagues believe this makes their school more welcoming than charters. But while enrollment is strong, and test scores have improved, they haven’t convinced everyone that their brand of public education is just as good.

William McKinley, whose son transferred into P.S. 161 last year from a charter run by the Success network, said he wished he could have stayed because the curriculum was so challenging. But there were family problems and a change of residence.

William McKinley and his son have tried both district and charter schools

“I wish charter schools was available when I was in school,” he said, adding “no offense” to a guidance counselor who had come outside during dismissal to talk to him about his child’s homework.

McKinley hasn’t given up, though. This fall he plans to fill out applications so his son can enter the lotteries for a charter middle school.