A recent article in Reuters, one that received a great deal of attention, sheds light on practices that some charter schools are using essentially to screen students who apply for admission. These policies include requiring long and difficult applications, family interviews, parental contracts, and even demonstrations of past academic performance.

It remains unclear how common these practices might be in the grand scheme of things, but regardless of how frequently they occur, most of these tactics are terrible, perhaps even illegal, and should be stopped. At the same time, there are two side points to keep in mind when you hear about charges such as these, as well as the accusations (and denials) of charter exclusion and segregation that tend to follow.

The first is that some degree of (self-)sorting and segregation of students by abilities, interests and other characteristics is part of the deal in a choice-based system. The second point is that screening and segregation are most certainly not unique to charter/private schools, and one primary reason is that there is, in a sense, already a lot of choice among regular public schools.

Let’s start with the first point. The idea of school choice is that independently-operated schools (including, perhaps, district and private schools) all compete for student enrollment. Students and parents choose those that are best-suited for them. The schools that aren’t successful in attracting students fail and perhaps close, while those that are successful thrive and grow. This competition, so the story goes, spurs innovation.

So, in the “traditional” model, public schools are supposed to be “general practitioners” – they must accept all students and serve them well. The charter/choice model, on the other hand, takes a somewhat different view – schools must accept those who apply, but different models will work well for different students. If we make schools compete for those students by giving their parents a choice, this will encourage schools to develop varying models, and to attract and retain those students for whom their approach is well-suited.

Without question, in a full blown choice-based system, simple geographical reality means that most schools within a district would have to maintain some kind of “general appeal” in order to remain viable (and that’s one reason why the majority of U.S. charters stick to their mission of accepting all comers and doing the best they can).

However, particularly in large, densely populated areas, there is room for schools to develop more “specialized” approaches, and it’s plausible to believe that many would attract/retain students who, on the whole, share certain characteristics (even if those traits are tough to measure with standard educational and demographic variables). Charter schools may hold random lotteries, but the whole idea of choice is that selection and deselection should not be random.

For example, the flagship model of the charter movement is the high-cost, high-intensity approach of so-called “no excuses” schools, which rely on practices such as tutoring, extremely long school days and rigid discipline policies. But not all students, regardless of their backgrounds, thrive under these conditions, and so some of them leave (or don’t apply in the first place). Despite all the controversy about this selection and attrition, it is a crucial element of a choice-based system – students who don’t fit in well with a given approach will go elsewhere.

Obviously, this is not at all comparable to reprehensibly burdensome application processes, but the end result – the sorting/segregation of students with different interests and abilities into different schools – is similar.

In this sense, the practices in the Reuters article represent terrible, misguided attempts to pre-engineer an outcome that the theory of school choice predicts would to some extent occur “naturally,” as parents and students selected into schools that fit their needs, and deselected out of schools that did not. And, if the theory holds up in practice, other schools would adapt by offering different models; there would be “something for everyone.”

What seems to have happened instead, at least in some places, is that this process has been distorted into a competition less for students than for crude test-based measures such as absolute proficiency rates. As a result, the specialization that you might expect from charter sectors tends to focus on higher-scoring students and intensive test-boosting approaches (though there are of course exceptions).

In other words, one might speculate that the sheer extent to which raw absolute testing outcomes are judge and jury serves as an impediment to the “something for everyone” end goal of school choice. So long as these measures are the coin of the realm, operators will tend to compete and innovate for higher test scores, and there may be less incentive to cater to constituencies or develop/expand models that are not necessarily compatible with this priority.

In any case, charter advocates should (and did) condemn the practices in the Reuters article. However, it’s important to note that the school choice vision not only entails some degree of sorting and segregation of students based on needs, abilities and interests, but may actually require it in order to work. It makes little sense for supporters (or opponents) to imply otherwise.

This brings us to the second, somewhat simpler point – screening and exclusion are not unique to charter (or private) schools. In a sense, they occur every day in regular public schools. Parents choose homes (or relocate) based in part on the quality of the schools in a given district (or neighborhood). Schools compete for these parents, and their success in doing so influences and is influenced by home and land prices within their boundaries.

These regular public schools take everyone they get, but there is a de facto screening process of sorts, by which entry into the schools requires income sufficient to live in the area. Put simply, if you can’t afford to live in a “good” school district, your children can’t attend its schools. That is one big reason why regular public schools are heavily segregated by race, ethnicity and income.

In this sense, those who rail against school choice do not seem well-attuned to the fact that a system of choice exists – albeit in a qualitatively different form – throughout the nation’s regular public schools. Similarly, those who criticize charter schools for increasing segregation should acknowledge that U.S. schools are heavily segregated with or without charter schools. And that seems like an issue we can all agree should be addressed, regardless of our views on school governance.