Here in Jersey, Uncommon runs a charter named North Star Academy, based in Newark. And if you want to know about Jersey, you gotta listen to some Bruce (Baker) [all emphases mine]:
Read the whole thing, then marvel that Eli Broad thinks that charters that give up on kids who struggle in school should be rewarded.If we take the 2009 assessments for each grade level, one interesting finding is that the charter schools serving lower grade levels in Newark are generally doing less well than the NPS average (red line). But, those schools that start at grade 5 seem to be picking up a population that right away is doing comparable or better than the NPS average. See, for example, TEAM and Greater Newark (comparable to NPS in their first grade – 5th – served) and, of course, North Star whose students perform well above NPS in their first year – likely not fully a North Star effect, but rather at least partly a selection effect (Lottery or not, it’s a different population than those served in the district). More strikingly, with each increase in grade level, proficiency rates climb dramatically toward 100% by 8th grade. Either they are simply doing an amazing job of bringing these kids to standards over a 3 year period… or … well… something else.The figure above looks at 6th, 7th, and 8th graders in the same year. That is, they aren’t the same kids over time doing better and better. But, even if we looked at 6th graders in one year, 7th graders the next year and 8th graders the following year, we wouldn’t necessarily be looking at the same kids. In fact, one really easy way to make cohort test scores rise is to systematically shed – push out – those students who perform less well each year. Sadly, NJDOE does not provide the individual student data necessary for such tracking. But there are a few other ways to explore this possibility.First, here are the cohort “attrition rates” based on 3 sequential cohorts for Newark Charter schools:In this figure, we can see that for the 2009 8th graders, North Star began with 122 5th graders and ended with 101 in 8th. The subsequent cohort also began with 122, and ended with 104. These are sizable attrition rates. Robert Treat, on the other hand, maintains cohorts of about 50 students – non-representative cohorts indeed – but without the same degree of attrition as North Star. Now, a school could maintain cohort size even with attrition if that school were to fill vacant slots with newly lotteried-in students. This, however, is risky to the performance status of the school, if performance status is the main selling point.Here’s what the cohort attrition looks like when tracked with the state assessment data.Here, I take two 8th grade cohorts and trace them backwards. I focus on General Test Takers only, and use the ASK Math assessment data in this case. Quick note about those data – Scores across all schools tend to drop in 7th grade due to cut-score placement (not because kids get dumber in 7th grade and wise up again in 8th). The top section of the table looks at the failure rates and number of test takers for the 6th grade in 2005-06, 7th in 2006-07 and 8th in 2007-08. Over this time period, North Star drops 38% of its general test takers. And, cuts the already low failure rate from nearly 12% to 0%. Greater Newark also drops over 30% of test takers in the cohort, and reaps significant reductions in failures (partially proficient) in the process.The bottom half of the table shows the next cohort in sequence. For this cohort, North Star sheds 21% of test takers between grade 6 and 8, and cuts failure rates nearly in half – starting low to begin with (starting low in the previous grade level, 5th grade, the entry year for the school). Gray and Greater Newark also shed significant numbers of students and Greater Newark in particular sees significant reductions in share of non(uh… partially)proficient students.My point here is not that these are bad schools, or that they are necessarily engaging in any particular immoral or unethical activity. But rather, that a significant portion of the apparent success of schools like North Star is a) attributable to the demographically different population they serve to begin with and b) attributable to the patterns of student attrition that occur within cohorts over time.
If you push kids out of your charter, I might give you a quarter million dollars!