Chicago: The Mayor We Have vs the Mayor We Need

"Chicago Principal Lays Waste to Rahm Emanuel's Campaign Lies in Five Minutes"
Takes on Rahm's claims about Kindergarten, Graduation Rates, Pensions, and Violence

But CPS has selective enrollment public schools that skew the results...

But CPS has selective enrollment schools that skew the results.  What happens when you remove these schools from the analysis?

• The Sun-Times analysis did not include selective enrollment schools.
• I remove them from my analysis when I eliminated all high attainment public and charter schools from the analysis (see note below). In that analysis the public school growth percentile number was 64 while the charter growth percentile was 29.

• The assumption behind the question about selective enrollment schools is not correct, and it's one of the main misinterpretations of NWEA growth data. I hear it every time I talk about MAP data. Selective schools' growth percentiles are calculated against other schools that got the same growth percentile in the first administration of the test.  Put simply, their percentiles are generated by comparing them to other schools across the U.S. with equally high performing students. It answers the question, "How much growth did they get compared to other high performing schools?"  For example one of CPS's selective academic centers has the highest average attainment in Chicago.  However, their growth percentile is only 76, which ranks 143rd in the district.  Another selective school--has the 35th highest math attainment score in the city but is at the 2nd growth percentile, one of the worst in the district, ranking 473rd out of 490.  CPS recently amended its performance policy to protect the mayor's prized selective enrollment schools from the embarrassment their low growth numbers would cause them if they were evaluated the same way neighborhood schools are.

• The MAP "growth" measure is as as close to an apples-to-apples comparison as is available, so there is no need to remove any type of school from the analysis. Still, the Sun-Times removed them anyway and charter schools still feel far short of public neighborhood schools in terms of fostering academic growth in their students.

Note:  I excluded schools that have 50% or more of their students scoring above average in attainment.  That ensured I was left with schools that served a predominantly low performing student body which obviously excluded all selective enrollment schools.  I did that by sorting the spreadsheet by the "% at/above national average" column and including only those schools whose percentage was below 50.  The CPS data specialist then processed those schools into CPS's "School Growth Calculator" to reach our findings.

But charters and turnarounds target the lowest performing students...

Question: What about the fact that charters and particularly turnarounds target the lowest performing kids -- which may partially explain their weak performance?

Response

• If this were so, then charters should have fared much better when I removed the highest performing half of CPS and charter schools from the analysis.  However, the difference was still substantial.  In short, there are still more public schools with low performing students than charter or turnaround schools with low performing students.  The public schools, however, got more academic growth from these students.
• The assumption of the question is incorrect.  Charters do not have the lowest attaining students; they have the lowest growth students.  If the CPS NWEA data spreadsheet is sorted by attainment and then by growth you will see that there are not as many charters at the bottom of attainment as there are at the bottom of the growth list.  This means that charters are not typically enrolling the lowest of the low attaining students. They're enrolling the highest of the low attaining students and not doing much to foster any growth in those students. In order to even attend a charter school a parent has to enter his or her child into a lottery process.  It is likely that a student whose parent is involved enough to engage that process is higher performing than students whose parents do not.  This may explain why charter attainment is not as low as its growth. They enroll students whose attainment his relatively higher that their peers. However, the data indicates that their teaching and learning is not comparable to that which occurs in Chicago's public schools.
• Turnaround schools (and charters) get their percentile ranks from a comparison to schools whose students got the same average RIT score as their students on the "pre-test." If the average AUSL score was 150, then they only compared that turnaround school to other schools across the U.S. whose average RIT scores was 150. They are being ranked in relationship to schools across the U.S. whose attainment average was the same as theirs in the pre-test. It's apples-to-apples. There is no disadvantage based on the students a school serves because they're being compared to schools with students whose attainment is the same as theirs. The charters and turnarounds had similar students to the schools they're being compared to, but they got far less growth.
• As I stated in the Op-Ed, the mantra of the charter/turnaround school choice movement has always "No excuses!"  My how things change.