Charter school students in California significantly outperformed similar students in nearby traditional public schools in reading and scored about the same in math, according to a comprehensive study of pre-pandemic test results of charter schools nationwide, released earlier this month.
The gap between California charter and district schools in reading achievement has widened since the first report 14 years ago by the Center for Research on Education Outcomes at Stanford University. There has been steady progress in math as well; charter schools’ scores were significantly behind in the first study in 2009.
This was particularly true when the difference in test scores was translated into learning gains or losses for multisite charter management organizations operating in California. For example, when compared with similar students in district schools, students in Los Angeles-based Alliance College-Ready Public Schools gained the equivalent of 107 days in additional learning, about 40% of a year. Students in Bay Area-based Rocketship Public Schools gained three-quarters of a year in additional learning days in math, based on CREDO’s methodology.
CREDO designated 32 California charter management organizations as “gap-busters,” whose average achievement exceeded the state average, and whose historically marginalized students showed growth that was strong or stronger than their non-marginalized peers in the same schools; 22 CMOs excelled in both math and reading, including ACE Charter Schools in San José, Para Los Niños in Los Angeles and King-Chavez Neighborhood of Schools in San Diego.
Charter schools are independently run public schools. Managed by nonprofit boards of trustees, they are not bound by some requirements of the state education code while being held to many of the same accountability, teacher credentialing and testing mandates.
About 1 in 9 California public school students — 685,000 out of 5.85 million students — attended one of about 1,300 charter schools in 2022-23. Although California has the largest number of charter schools and students in the nation, CREDO found their performance gains, relative to similar district school students, were smaller than charter students in a dozen of the 29 states covered by the study, plus Washington, D.C., and New York City. Charter school students in a dozen states also outperformed their peers in math; in California, the difference was not significant. The differential was biggest in Massachusetts, Illinois, Rhode Island and New York state charter schools.
Charter school and similar district students in all other states performed about the same, except for one state where charter school students performed worse in reading (Oregon) and three states where they performed worse in math (Oregon, South Carolina and Ohio).
Progress over time
CREDO’s report, released earlier this month, is its third tracking charter school students since 2009. The latest covered 2014–2019 and included four years of test results.
“Between the 2009 and 2023 studies, against a backdrop of flat performance for the nation, the trend of learning gains for students enrolled in charter schools is both large and positive,” the report said.
As in its past studies, CREDO’s analysis found wide differences in which students benefited from attending a charter school in California.
Black and Hispanic students and students from lower-income families excelled relative to similar students in typical district schools in reading and math, while white students and especially students with disabilities did significantly worse in both math and reading than their peers. English language learners in California charter schools did slightly better than district school peers in reading but significantly better in math.
“We are pleased to see that California’s charter schools are performing particularly well with historically underserved students and improving over time,” said Elizabeth Robitaille, chief schools officer for the California Charter Schools Association.