There is useful information to be plucked from the mess of charter school studies. This analysis does the hard work for us (this is the third such study in a series). The authors evaluated 58 recent (2001 or later) comparisons of charter school and district school performance, evaluating each by its methodology and findings.
Of the 58 studies, 25 were “snapshot studies” (which looked at data from separate points in time) and 33 evaluated performance change over time. The authors caution against reading much into the former.
Among the latter, they explain, it’s worth checking out sample sizes. Also important: against what schools or students are charters being compared? The best comparisons use random experimental designs that ”minimize the chance that charter school attenders are somehow different from non-attenders in ways that influence achievement,” such as their family situation.
Of the 33 value-added studies, 16 found performance gains in charters that were larger than other public schools, and 7 found charter school gains larger in certain school categories (e.g., elementary schools, schools for at risk students, etc.).
This report also notes that, while we are awash in studies of student achievement, we lack substantial research that evaluates chartering as a policy (”how to change the way authorizing works; how to change charter schools’ funding and regulatory regimes”; etc.). Much of this we already knew, but it’s good to stay on top of things.
Read it here