Charter schools that start out doing poorly aren’t likely to improve, and charters that are successful from the beginning most often stay that way, according to a new study by researchers at Stanford University.

The report, done by Stanford’s Center for Research on Education Outcomes (CREDO) and funded by the Robertson Foundation, also found that charter management organizations on average do not do a “dramatically better” job than traditional public schools or charter schools that are individually managed.

One caveat to the findings: They are based on standardized test scores, and there are big concerns among educators and researchers as to whether student achievement should be primarily based on these scores given the limitations of test design and other factors. I am writing about the report because it is going to be cited in the school reform debate, as previous CREDO reports have been, especially the 2009 report that showed that only 17 percent of charter schools across the board get better test scores than traditional schools.