Charter Schools and Teacher Evaluations: A Perspective

A former member of the San Carlos School Board reflects on charter and traditional public school performance.

I read with interest the recent Patch article about charter schools and teacher evaluations. I'd like to share the perspective I gained from ten years on the San Carlos School Board as regards charter and traditional public school performance.

Virtually every analysis I've seen on this topic ignores selection bias. An implicit assumption is made that the children attending public charter schools and public traditional schools reflect the same population.

At first blush that sounds reasonable. Both are open to all, neither charges tuition, and both are funded by public money. So their populations must be the same, right?

But that ignores several well known differentiating factors. Most charter schools make parent/family volunteering a necessity. In fact, until a recent change in charter law, many actually required "volunteering."

While all public schools encourage volunteerism, the emphasis on it at charters is much greater. This makes charters less attractive to families for whom volunteering would be difficult or impossible.

In addition, at least some charter schools discourage students with challenging learning issues from applying. By law, charter schools cannot turn away an applicant on that basis. But in practice things aren't so simple.

I personally witnessed a famous charter proponent counsel a charter oversight board on how to dance around the legal prohibition so as to save money. Another pretty much wrote "we're not for everyone" right into their charter.

Charters generally have to be sought out by families. They are not the "default option" when it comes to enrolling your child in public school. This, too, introduces a selection bias.

As another famous charter school proponent told me, "Only people who are willing to sacrifice for their kids have the time, energy and inclination to seek us out and go through our application process."

Does all of this matter in terms of differentiating the student populations of charter and traditional public schools? I believe the evidence shows it does. The authors of Freakonomics and SuperFreakonomics -- enjoyable books on "things we think we know" -- reported on the best study of selection bias in public education I've ever come across.

Several years ago the Chicago public school system shifted to an open enrollment process for all its high schools. Any middle school student could apply to any high school, regardless of service area boundaries. Schools that were oversubscribed held lotteries to determine who got in. No one got in just because of where they lived. The authors compared the educational outcomes of the winners and losers of those lotteries.

There was no significant difference in performance between the kids who won the lottery and the ones who lost. Apparently, being the kind of student who was motivated to make a choice regarding schooling meant you were the kind of student who would do well in school. It wasn’t the school that was important, it was wanting to do well in school.

This is consistent with analyses of standardized test results in California. Between 70 percent and 75 percent of the differences in standardized test scores between elementary schools can be explained by just three factors: the proportion of students from college-educated families; the proportion of students speaking English natively; and the proportion of students from poor economic circumstances. Every other factor – differences in funding, the impact of teacher performance, etc. -- is in the remaining 25 – 30 percent.

Does that mean we should forget about teacher performance? Of course not. But our debate would be more meaningful – more likely to create real positive change – if we remember to account for selection bias when making comparisons, and focus on the elephant in the room: where kids come from, and what they bring to school.

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Adam Heenan August 05, 2012 at 06:17 PM
Part I: The author has some things correct, and some things false. Yes, poverty, parental involvement, and an engaging curriculum at school are the top factors in determining student success. This statement however, is untrue: "[In Chicago] any middle school student could apply to any high school, regardless of service area boundaries. Schools that were oversubscribed held lotteries to determine who got in. No one got in just because of where they lived." I am in Chicago, and we never had Open Enrollment as such. For 30 years we have had magnet schools (I currently teach in one) that have "skimmed the best students" off the top (of the testers from middle school) regardless of what part of the city they come from. Those schools have gotten more resources, have the richest curriculum, have had the best scores (regardless of the kinds of tests they were taking), and have been subjected to very little (in most cases no) Centralized intervention (closings, turnarounds, charterization, reconstitution)...
Caroline Grannan August 05, 2012 at 06:22 PM
Great commentary. Also: Non-magnet public schools enroll students by default. All charter schools require families to specifically apply. Just that fact requires a level of motivation, attention and concern about education that should give charters an edge. In addition, charters are free to impose whatever additional hurdles they want, no matter what claims are made about accepting all applicants. San Francisco's most successful charter school has a 13-page enrollment application that requires multiple essay answers from the parent; as well as an essay by the student, transcripts and teacher recommendations. Clearly those requirements ensure a high degree of motivation and concern about education. And yes, charters notoriously have many ways to discourage students with special needs. The much-praised Green Dot charter chain has a handbook that explains how to counsel students with disabilities back to the school district. Despite all that, charters overall are no more successful than public schools. By the way, the issue of union-bashing is part of this discussion too. This fact puts that issue at rest for good: The states with weak or no teachers' unions consistently have the lowest achievement; and the most strongly unionized states have the highest. Those are the facts, so now you know that the union issue should no longer be on the table. www.parentsacrossamerica.org
Adam Heenan August 05, 2012 at 06:26 PM
Part II: ...However if you are a student who didn't well on standardized tests you were required to go to your neighborhood high school, many of which have been chronically under-resourced. Influential University of Chicago economists had stated goals of turning-around and charterizing (Before Race to the Top, this was called Renaissance 2010) schools in neighborhoods that "needed development" (gentrification) and using schools to enforce this. This has been a pattern not only in Chicago, but also replicated in Washington DC, NYC, Philadelphia, New Orleans, and Los Angeles. Standardized tests have been the blunt weapon used to falsely declare our public schools, students, and educators "failures," in order to be able to privatize them. In its latest form this has been dishonestly sold to parents as "school choice" with tools such as the "parent trigger." Yet the reality is that parents don;t want school choice. They want good schools. Period. We need equitable resources for all schools.
Mark Olbert August 05, 2012 at 10:30 PM
Adam (& others), Thanks for chiming in. The Chicago public school landscape is more complicated than I described, and even more complicated than the Freakonomics authors described. However, those authors concluded the system was capable of generating data on school choice worth analyzing. In case anyone is interested, here is the introduction to the section of Freakonomics I referred to : School choice came early to the Chicago Public School system. That’s because the CPS, like most urban school districts, had a disproportionate number of minority students. Despite the U.S. Supreme Court’s 1954 ruling in Brown v. Board of Education of Topeka, which dictated that schools be desegregated, many black CPS students continued to attend schools that were nearly all-black. So in 1980 the U.S. Department of Justice and the Chicago Board of Education teamed up to try to better integrate the city’s schools. It was decreed that incoming freshmen could apply to virtually any high school in the district. Levitt, Steven D.; Dubner, Stephen J. (2010-02-17). Freakonomics Rev Ed: (and Other Riddles of Modern Life) (P.S.) (p. 143). Harper Collins, Inc.. Kindle Edition.
Mark Olbert August 05, 2012 at 10:33 PM
Some additional documentation from Freakonomics, because they said it much better than I did: The answer will not be heartening to obsessive parents: in this case, school choice barely mattered at all. It is true that the Chicago students who entered the school-choice lottery were more likely to graduate than the students who didn’t— which seems to suggest that school choice does make a difference. But that’s an illusion. The proof is in this comparison: the students who won the lottery and went to a “better” school did no better than equivalent students who lost the lottery and were left behind. That is, a student who opted out of his neighborhood school was more likely to graduate whether or not he actually won the opportunity to go to a new school. What appears to be an advantage gained by going to a new school isn’t connected to the new school at all. What this means is that the students— and parents— who choose to opt out tend to be smarter and more academically motivated to begin with. But statistically, they gained no academic benefit by changing schools. Levitt, Steven D.; Dubner, Stephen J. (2010-02-17). Freakonomics Rev Ed: (and Other Riddles of Modern Life) (P.S.) (p. 144-145). Harper Collins, Inc.. Kindle Edition.


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