The Tricky Bit — How to Account for Selection Bias Now for the important question, in the context of these data and techniques, how did I compare students in choice schools to
students in traditional public school knowing that that difference in decision might be because of some unobservable characteristic obscuring the true comparison between choice students and traditional public school students?
Not exact matches
And we
know that, more often than not, the
students attending
traditional public schools in cities are
in intensely segregated
schools.
Here is what we
know:
students in urban areas do significantly better
in school if they attend a charter
schools than if they attend a
traditional public school.
The only way to
know with confidence whether charters cause better outcomes is to look at randomized control trials (RCTs)
in which
students are assigned by lottery to attending a charter
school or a
traditional public school.
Even if a charter or private
school were
no better than a
traditional forced - choice
public school, the fact that parents and
students themselves choose the
school may mean they perceive distinct advantages
in it, real or not.
Known as the CREDO study, it evaluated
student progress on math tests
in half the nation's five thousand charter
schools and concluded that 17 percent were superior to a matched
traditional public school; 37 percent were worse than the
public school; and the remaining 46 percent had academic gains no different from that of a similar
public school.
At the transformation of
traditional public school districts to non-
traditional charter
school districts
in New Orleans, birthed a group of fearless
student activists called the Carver Five
known throughout the city as the C5!
In fact, many high - performing
traditional public schools — particularly magnets and selective enrollments — enforce a
no - excuses policy by screening the
students who enter their
school.
Traditional public schools intensify their improvement efforts
in response to these new choices available for families, but are
no longer burdened with the challenge of trying to be all things to all
students.
We
know this because of the more than 63,500
students attending F
schools in traditional public school districts, three - quarters of those children — more than 49,000
students — are poor enough to receive free or reduced price lunches.
Second, beyond selection bias, we don't
know if there are other factors that affect achievement that we are not accounting for that are systematically different between
students in choice
schools and
students in traditional public schools.
However,
students who attended
public schools that were granted considerable autonomy but kept the union —
known as «pilot»
schools — performed
no better than they would have had they remained
in a
traditional Boston
public school.