@TrueEpic08 what say you?
You want me to get involved in this toxic debate?
In any event, I'm always wary of a few things in these reports. The kind of data collected and interpretation of that data is one thing. How they selected students or, to generalize, defined the sample is another thing. But the big, big issue is how this type of research ends up being used, i.e., how it ends up defining the charter school v. public school debate.
What usually ends up happening is this: a study comes out stating, in some way, that charters are better than publics. This, then, leads to a wave of support for charters and against publics that ignores the financial and social realities of the differences between the two (actual and perceived), which usually goes to the issue of what the function of education and these kinds of schools (and their teaching methods) actually are.
Really, anyone who gives a damn about the state of education in America should be hoping that these stats become more even over time; they should be hoping against hope that public schools start looking better vis a vis charters, because if they don't, we get the worst of both worlds in education. That is: a semi-privatized system of education that uses data and various studies (both legitimate and, often, dubious) to manipulate the debate in favor of charters and away from public schools accessible to all students. And often times, this isn't for the sake of better education for all, but for the exploitation of a segment of the populace for the sake of making education profitable.
Now, I'm not trying to discredit this study, I haven't looked at it closely enough (and there are other studies of charter schools that expose the issues of analyzing performance, attrition rates of students and teachers, lack of applicability to public schools, dubious test results, etc). But I will say that, if the data is legitimate (I want to take a closer look at how they selected and tracked the students, as well as how they measured performance in math and reading, because that isn't specified AT ALL in the OP's article), it only means so much, because it doesn't take into account the differences between charter and public schools in terms of autonomy, funding, student selection, etc. that are issues of policy and sociological conditions than merely issues of student performance. Any study that means to suggest modifications to education policy that doesn't take into account both the state of affairs that have created publics and charters as we know them today, as well as the explicitly divisive and capitalistic discourse that surrounds education, usually just ends up a political tool meant to create more division between the two for one purpose or another, rather than a movement toward a real solution.
Also, consider the source as well. Just saying.