Comparing public and private schools is difficult; in part b/c private schools are allowed to select their students -- both before and during enrollment. Having taught in a school overrun with discipline problems, I tend to believe that the ability to "get rid of" students (having an "exit door," if you will) has a potentially large influence on the climate of a school.
Charter schools are much more similar to traditional public schools than are private schools; but we still run into some of the same problems when trying to compare them -- particularly regarding selection of students. The vast majority of charter schools select students through a lottery, so they can't just select the top x number of students, but parents still have to take the extra step of applying to the school. The differences, if any exist, between parents that apply and do not apply for enrollment in charter schools is another topic for another time. What I hear mentioned less frequently is the extent to which charter schools have exit doors.
At my school, a number of kids went through every disciplinary procedure possible (reprimand, phone calls, detention, parent meeting, classroom switch, suspension, etc.) and continued to harass and disrupt both their teacher(s) and classmates. At that point, the school essentially had its hands tied behind its back. I believe a couple eventually went to alternative schools, but most hung around and continued to cause headaches. You could imagine the effect it might have on the climate of the school if we could simply say "you are no longer welcome here." The child, and his/her behavior, would no longer negatively influence the school -- and other students would know that they would no longer be welcome if they chose to behave the same way.
The problem with this, of course, is what happens to the child once they're disinvited from that school -- they still have a right to an education.
Anyway, I've always wondered whether charter schools have their hands tied behind their backs to the same extent in these circumstances. I've seen video of a new cohort of kids at a KIPP school being told by the principal that they should leave if they don't like the way the school is run -- so I suspect that at least minor differences exist. My guess is that, legally, a charter school has no more right to expel a student than does a traditional public school but, given that the student is there by choice and has a free fallback option, I'd also guess that a charter school would have an easier time convincing a student to leave.
Imagine the following scenario: a principal tells a parent that their child is not doing well in their school and would probably do better in a different environment. In a traditional public school, it's going to be tough for a parent to find another place to put their child. They're either going to have to pay for a private school, apply to a charter school, or move (or apply to enroll in a different public school if NCLB says they can and seats are open). In a charter school, meanwhile, the parent has the option to enroll their child in the local public school for free -- and probably the next day.
This whole explanation is a long-winded way of saying that I find the statistics in this post about KIPP schools around San Francisco very interesting (hat tip: Education Policy Blog). The author breaks down the attrition statistics of the three Bay Area KIPP schools. I remember reading about this in the news, and thinking that it was interesting but far too early to conclude anything. In short, the three schools all enrolled about half as many students in eighth grade as originally started out in fifth grade -- a pretty high rate of attrition. That statistic, in and of itself, however, isn't all that meaningful. The students were from the first cohort to enter the schools, and there are growing pains everywhere. The students could have left for any number of reasons.
What I find interesting is the attrition rate of African-American males -- which far exceeded the overall attrition rate in all three schools. Given that, nationally, African-American males are both the lowest achieving and the most likely to be disciplined, this raises important questions about whether these schools weed out certain types of students.
The first cohorts to enter the three schools had 13, 24, and 35 African-American males enrolled in 5th grade. By the beginning of 8th grade, they had 3, 8, and 8 left -- meaning that, across all three schools, 72 started and only 17 (21%) were left by the start of 8th grade (I don't know how many actually finished).
This, of course, proves nothing -- but it's circumstantial evidence that merits further investigation.
Ok, so let's say that these three schools are, in fact, weeding out the weakest and least-focused students. A charter school that regularly makes use of their "exit door" will never be comparable to a traditional public school that doesn't have this option. So what? Maybe if all charter schools did this, and we created more charter schools, then more excellent schools would exist. In other words, maybe it's an advantage to charter schools that merits more of them rather than hand-wringing. Though somewhat perverse, I don't think that argument is without merit. But I see a major problem:
The kids that are "asked" to leave have to end up somewhere. In a scenario where more charter schools exist, maybe they simply end up at another charter school -- and maybe they learn their lesson, or simply fit in better . . . or maybe they continue to wreak havoc. But in our current situation, I have to believe that it's most likely that they will end up back in the public school for which they're zoned. In which case, it's likely that the other students in the school suffer from the disruptions that this new student creates. This not only creates a competitive disadvantage for the school, it also punishes all students who choose to enroll in the traditional public school rather than a charter school. And that's simply not fair to those students.
Granted, this is mostly speculation -- so don't read this and then decide that charter schools are evil or that expulsion is the ultimate solution -- but it's at least logical to assume that this problem might exist.