Charter students in middle schools also stand out academically after they enroll in charters, making faster gains than similar students in traditional schools, according to the study.
The findings add more fuel to the debate over charters but stops well short of settling the question of whether these schools are more effective at educating students.
Charter school performance has come under scrutiny recently as a group of advocates and donors, spearheaded by the Eli and Edythe Broad Foundation, developed a proposal to enroll half of L.A. Unified School District students in charters. The plan, if pursued, could threaten the solvency of the school system, some district officials say.
These advocates insisted, in a draft proposal obtained by The Times, that charter schools are successful and that L.A. Unified is failing.
Charters are attracting increasing numbers of families — about 16% of district enrollment — and L.A. Unified has the most charter students — about 100,000 — of any district in the nation.
These schools are publicly funded and exempt from some rules that govern other campuses. Most are non-union.
Charter supporters have cited other research using Los Angeles data to assert that these schools provide a better education. But if students already are academically superior when they enter, that claim is undermined. The research also raises the question of whether some charter operators are trying to enroll higher-achieving students or trying to exclude those less likely to perform well.
“We are not suggesting that charter schools unfairly cherry-pick stronger students or more resourceful families,” said study co-author Bruce Fuller, professor of education and public policy at UC Berkeley. “However, parents with more savvy or time seem more likely to seek out stronger schools.”
Under state law, charters must accept all students, and they must conduct a random lottery when there are more applicants than capacity. There have been charters that have skirted these rules, although other charters have taken steps to increase the number of low-income, minority students who get in, and those students typically have lower test scores.
Because Fuller’s study relied on test scores, it was limited to those grades in which students are tested.
The California Charter Schools Assn. noted that Fuller concluded that second-graders in charters started off higher academically by looking at their test scores in second grade, the earliest year available for test scores. The group said that these higher test scores could be a result of charters offering a superior education in kindergarten and first grade — and not because the charter students started off as higher achieving.
The researchers tried to account for this issue, however, by looking separately at students who switched from traditional schools to charters after second grade.
The charter group also challenged the sample size in portions of the study, among other things.
“It is unfortunate that Dr. Fuller and his team seem unwilling to acknowledge that the credit for charter schools’ superior performance goes to the highly talented and driven educators who, with a healthy balance of autonomy and oversight, have innovated and adapted to their unique communities’ and students’ needs, yielding student gains that should be celebrated, not snubbed,” the association said in a statement.
The charter association also criticized Fuller for including so-called affiliated charters, which are district-run and lack the independence and operating structure of charters that are fully independent. Fuller countered that the overall findings were unchanged when he removed the district-run campuses.
District officials say that the better comparison is between charters and magnet schools that offer specific programs for students who voluntarily enroll.
The UC Berkeley study tracked 66,000 students from 2007 through 2011, using state test data and information about students provided by the California Department of Education and L.A. Unified. Fuller’s co-authors were Hyo Jeong Shin and Luke Dauter. The study was funded by the Spencer Foundation of Chicago and the PACE center, based at Stanford University.
Charter supporters have defended their efforts by noting that their students are comparable with those in district schools in terms of family income level. Moreover, other researchers have concluded that L.A. charter schools with similar students score higher than nearby district schools in direct comparisons. But Fuller’s study suggests that there are subtle but important differences between charter students and those in traditional campuses.
Charter critics also have asserted that there are less subtle distinctions, accusing some charters of limiting the number of students with moderate to severe disabilities or those who have behavioral issues.
“The main takeaway of the new study is that it shows that many charter schools are in fact selecting higher-performing students and excluding lower-performing students,” said Alex Caputo-Pearl, president of United Teachers Los Angeles, which has criticized charters. “Whether it is intentional in-your-face exclusion or excluding because that’s how the process works — either way they’re not serving a proportionate share of lower-performing students and that’s not good for a public education system.”
School board President Steve Zimmer said the results of the research weren't “earth-shattering” for either side of the debate.
“When you’re talking about the same kids in the same situations, we’re not talking about huge breakthroughs for charters,” said Zimmer, who has supported most petitions to open or renew charters but also has criticized the rapid growth of charters as harmful to the school system.
He added it would be important to learn why charters appear to benefit middle school students.
“The data doesn’t indicate what charter middle schools are doing better, but it does give us some suggestion that there might be some effective approaches,” Zimmer said.
The Times receives funding for its digital initiative, Education Matters, from the California Endowment, the Wasserman Foundation and the Baxter Family Foundation. The California Community Foundation and United Way of Greater Los Angeles administer grants from the Broad Foundation to support this effort. Under terms of the grants, The Times retains complete control over editorial content.