Greater attention for students, high expectations, and good teachers: These are the factors that a new report on small high schools found are important for running a great school.

More surprising were the report’s findings about what isn’t as important, based on interviews with 100 teachers and principals who work in the city’s top small high schools. School support networks rank far down on the list, for instance.

The report, called Inside Success: Strategies of 25 Effective Small High Schools in NYC, was released on Thursday by The Research Alliance for New York City Schools. It’s the latest look at the 250 small high schools that opened between 2002 and 2008 with the help of $150 million in private funding from the Gates Foundation.

The interviews reveal lessons about sustainability that could help Department of Education officials as the city’s many new small high schools grow.

The high costs of a hard-charging staff: Burn out

Juggling school-wide activities, teaching extra classes, and running after-school clubs are among the roles that teachers and principals play at small schools, especially in their growing years. Handling those peripheral duties is one area where teachers said large high schools have an edge.

“The assistant principal of instruction is not only supporting teachers, but she’s also the school accountant,” one teacher noted in the report.

The need to have a committed group of teachers and administrators comes at a cost, according to the report. Though principal turnover wasn’t high, nearly one in four teachers at the schools in the study left each year, a higher turnover rate than that of other high schools in the city.

Adriana Villavicencio, a New York University researcher who authored the report, said that not all of the principals saw the higher turnover rates as detrimental, though.

“The principals often saw it as a good thing if the teacher wasn’t a good fit in their school building,” she said.

Networks aren’t that important, educators say

Some principals have publicly lobbied the new administration to keep in place the network structure through which they receive professional development, help with budgeting, and other types of support. But the top small high schools say it wasn’t a big factor in their success, something that came as a surprise to researchers because partnerships with external organizations were a primary component of the small school model.

Another basic trait of the small schools model that teachers and principals saw as relatively unimportant was that they should be created with professional themes in mind and have names to reflect them.

Small schools give students more attention—until they get bigger

Some principals noted that it became harder to maintain a school’s personal feel as they enrolled more students. Teachers had more phone calls home to make, small advisory groups swelled, and principals weren’t able to hire more staff.

The schools examined in the study enrolled an average of 426 students, an average of 37 more students than small schools in the city served. Five of the schools were serving over 500 students—much higher than the 400-student cap that is a part of the small-school model.

“As this school has been growing, it’s become difficult to make those phone calls to the parents,” according to an interview excerpt with one teacher. “Before, we have had 14 kids per teacher, now it’s way more than 14 kids. It’s a big load to go home over the weekend and call 40 parents or so to let them know how each student is doing in each of their classes.”

Villavicencio said the schools also had a two-to-three year grace period in their early years during which the department sent fewer students with special needs. Once they aged out, some schools may have struggled to adjust.

Principals think teachers matter more than teachers think teachers matter

Principals frequently cited their teachers’ quality, commitment and capacity to play different roles in the school as a top factor in their schools’ success.

“The success of [this school] is driven by the staff here,” one principal said in an interview. “I mean, there’s a huge commitment of teachers to come in early and stay late and give up their lunch periods with not a consideration of compensation.”

Teachers were less likely to pin a school’s success on their individual work, noted Villavicencio, one of the report’s authors.

“For a principal who is looking globally at the school and has to deal with a lot of the hiring and human resources management, I think that’s something that’s a little bit more on their minds,” Villavicencio said.

A consensus, this is not

Agreeing on what makes a good school is a tough task, even for the people who work in one every day.

Of the three “core” factors that the report identifies as being essential to a school’s success, just one —personalized learning environments— emerged as universally important. Teachers in 10 of the study’s 25 focus groups was what made their school tick, while just five out of 25 principals mentioned having high academic expectations in their interviews.

Villavicencio said that despite the lack of agreement among interviewees, teacher quality and expectations still stuck out further than any other traits that we mentioned, such as professional development or external partnerships.

A better idea of what makes a small school work might come in a subsequent report, set to be released in 2015 that will survey teachers in three times as many schools.