Margaret E. Raymond, CREDO, Hoover Institution at Stanford University
May 2003
Though California has had charter schools for almost a decade, little research has examined their impact on student achievement. This new report from Stanford's Center for Research on Educational Outcomes attempts to fill that void by comparing charter schools and traditional public schools on two dimensions. The first is a school's Academic Performance Index (API), a weighted average of scores earned by students on standardized exams in grades 3-11. The second is gain scores: average student achievement increases from one year to the next. The bottom line is that charter students are performing slightly below students as a whole but are ahead in year-to-year gains. Raymond found that, when the average API for charter schools was compared against the average API for all traditional public schools (including districts with high performing public schools and no charters, which often don't have students who are demographically comparable to districts with charters), the charters' API is slightly lower though not statistically significant. When it comes to gain scores, though, Raymond found that charter high schools show statistically significant year-to-year gains compared to their public school counterparts (elementary schools also show greater year-to-year gains, though these are not statistically significant). As Raymond notes, the pool of charters includes many new schools that are "experiencing all the disruption of starting a new enterprise." So the fact that they are doing as well or better than their traditional public school counterparts "raises interesting questions about their longer run performance." Read it for yourself at http://credo.stanford.edu/Performance%20of%20California%20Charter%20School.FINAL.complete.pdf.
