Charter school advocates have long held their more autonomous, flexible school models will work as laboratories, allowing best practices to be worked into traditional public schools.
The results of a Stanford University think-tank study found students in Los Angeles charter schools are outperforming their peers in traditional L.A. Unified schools. Marco Petruzzi, CEO of Green Dot, one of Los Angeles largest charter school chains said the success is in part because charters are sharing what works with each other.
"I believe in L.A. - one of the largest markets - there's been strong sharing of knowledge," he said. "There's a lot of sharing of what works, and what doesn't. There's a friendly, collaborative climate."
Patruzzi said L.A. Unified traditional schools are also trying to learn from best practices emerging from charters, but it's often hard for a district of more than 500,000 students to change course.
"Traditional schools are dealing with years and years of having built a system in a certain way and they need to deconstruct that," he said.
Rather than respond to the lower learning overall by students at traditional schools, L.A. Unified Superintendent John Deasy said the report, Charter School Performance in Los Angeles, actually shows success by the district.
The report's authors at the Center for Research and Education Outcomes, or CREDO, credited the district's oversight in picking good charters and keeping them in line.
"What we think we are seeing is very strong authorizing happening in Los Angeles," said Dev Davis, an author of the study.
"This is a formula that appears in other high performing charter communities," she added. "Flexibility coupled with strong authorizer accountability leads to benefits for students."
She gave no details on how those terms work on the ground.
L.A. Unified has the power to close charters down, but seldom does.
Davis and her peers found that, overall, Los Angeles charter school students averaged 50 more days of learning in reading and 79 more days in math compared to their peers at traditional L.A. Unified schools.
The study compared charter and traditional students of the same background, and found the widest gap between low-income Latinos. Those in charters are ahead 58 days of learning in reading and 115 days in math compared to their peers - nearly two-thirds a school year.
The results stand in contrast to CREDO's report last year which found charter schools nationwide weren't doing much better than traditional public schools.
CREDO would not disclose the funding source for the study. This is the first time it's looked at a specific district.