Don't Forget South Central (DFSC, as christened by K. Libby) has a love/hate relationship with the L.A. Times. On the one hand, its reporting is vastly slanted (the puff piece on charters last week is a primo example). However, many times it is our only source of information on the district we work in. So, reluctantly, we must refer to it for "information."
Below is a graphic from the so-called Times Special Report on Charter Schools. Although it can be interpreted in many ways, I see that Green Dot's schools (Charter Management Organizations) have the lowest proficiency averages of all the types of charter schools. The charters most closely affiliated with the District have the highest scores.
It seems that having some flexibility from District red tape may result in the highest test scores. The more you venture away into Green Dot territory, whose leaders have no background in education, the lower your test scores will be.
One thing to consider is that these scores are not growth scores. They do not show how a particular students scored after a year of instruction. In other words, if a charter enrolled lots of Advanced and Proficient students, then it is not a huge achievement to have the kids continue scoring that way. A better analysis would focus on average growth: after a year of instruction at a charter (or traditional school, or affiliated charter, etc) what was the average growth per student? That would maybe give the public a better idea of which system produces higher scores.
However, higher scores could be a reflection of the narrowing of the curriculum, a dynamic that occurs when schools choose to focus on the English and Math disciplines, because these are the ones measured by NCLB. Science and Social Studies and the Arts get...left behind.
Either way, the scores of Charter Management Organizations like Green Dot don't support the Times conclusion that they outperform traditional public schools by a gigantic margin, especially considering they are beneficiaries of a more motivated population of students and families.