Giving Compass' Take:

• A new study found that Boston charter schools were able to replicate success as they expanded their charter network.

• There is still some tension in Boston over the expansion of charter schools in the city. Do you think that the successes of charter schools overshadow other schools in the district?

• Read about parents and educators advocating for charter schools in other cities.

Excel Academy in Boston started as a single charter school in 2003. Nine years later, its leaders created a second school in the city, bringing their philosophy and some original staff members to the offshoot.

The network now spans four schools, and Nina Cronan, who once worked at the original campus and currently leads one of the newer schools, said they have key similarities: their college pennants on display, their exams and curriculum, even their policy that teachers rotate classrooms while students stay put.

Now a new study finds that Excel and the other Boston charters maintained their high performance as they rapidly grew — perhaps because of how closely they were able to emulate original schools’ practices.

The results are significant because they illustrate a potential benefit of one controversial aspect of some charter school networks: “a highly standardized school model that limits teacher discretion,” as the researchers put it. The findings also differ from some past research, which has found that some networks see their academic performance weaken a bit as they grow.

So what’s going on in Boston? The new study, which has not been formally peer-reviewed, is the latest in a long line of research showing that students improve substantially on tests after attending one of the city’s charter schools.

Most of Boston’s charter schools seem to use a “no excuses” approach, a somewhat ill-defined term that many charter leaders now reject as pejorative. The researchers define it as including strict behavior standards, a college prep curriculum, student uniforms, and “high expectations.”

Comparisons to Boston’s district schools are tricky, since the data is limited. But Boston’s charters generally had fewer experienced and credentialed teachers, longer school days and higher suspension rates. Others are likely to react skeptically, especially since the Boston results are limited to test scores.

Read the full article about Boston charter schools by Matt Barnum at Chalkbeat.