In a recent report, the California Charter School Association claims that the state’s charter schools are narrowing the Black-White achievement gap. Not so, explains Arizona State University professor David Garcia, an expert on charter school research, in a review of the CCSA study conducted for the National Education Policy Center (NEPC) at the University of Colorado Boulder.
Garcia finds flaws in the report’s methods, and he explains that the gap is “largely unaffected by charter enrollment.” Further, Garcia pours cold water on the report’s claim that innovative practices are at work in charter schools that aren’t found in traditional public schools.
Garcia reviewed Chartering and Choice as an Achievement Gap-Closing Reform: The success of California charter schools in promoting African American Achievement, published by the California Charter Schools Association, for the NEPC’s Think Twice think tank review project.
In his review,Garcia notes that the report claims that African American students attending California charter schools scored, on average, 19 points higher than the average for African Americans attending traditional schools on California’s Academic Performance Index (API), which is derived from statewide standardized tests under the state’s accountability system for public schools. The report also claims that California charter schools are reversing the trend of low academic achievement among African American students and effectively closing the Black-White achievement gap.
Garcia observes that the data in the report itself show that “African Americans in California charter schools started out higher and actually lost ground relative to traditional public schools over time,” with traditional public schools outgaining charter schools by 6 points. Moreover, he writes, “closing the achievement gap requires that African American students make more gains relative to White students – and by this definition, traditional public schools outperformed charter schools.”
Garcia also points out that the report’s confusing and poorly supported claims are due in part to its “shotgun approach”: “it includes so many findings that it loses track of which schools are included in which findings.”
According to Garcia, the most positive spin that can be put on the evidence is that while the gap is still wide, it might be growing at a slower pace for charter school students. Even this interpretation, however, is not well-supported by the data or analyses in the new report. This is largely because the main statistical model presented in the report has several prominent weaknesses. It accounts for only 3-6 percent of overall variance, meaning that the observed outcome differences are explained overwhelmingly by factors not included in the authors’ model. One cannot make reliable policy decisions based on such a weak model.
Moreover, throughout the report, the authors chose to set aside differences in socio-economic status as regards charter elementary and middle schools, not considering the likely effects those differences have on the measured outcomes. The sole exception occurs when the performance numbers appear to favor traditional public high schools, in which case the authors point to socio-economic status differences as the explanation.
The report’s greatest strength, Garcia writes, is that it again demonstrates what other studies have found: namely, that “charter schools are of variable quality, and there are very few innovations in charter school practices as a whole that are not also present in traditional public schools.” In the main, however, he says: “The most useful policy briefs are concise as well as accurate. This report is lacking on both counts.”