Interview with the Chicago Reader's Ben Joravsky on what Mayor Emanuel's decision to send his kids to a private school says, and more.

Interview with the Chicago Reader's Ben Joravsky on whether Chicago Public Schools' do-not-hire practices have changed under Supt. Brizard, and more.

Interview with the Chicago Reader's Ben Joravsky on whether teachers' 75 percent minimum membership requirement for a strike vote hobbles their union, and more.

Interview with the Chicago Reader's Ben Joravsky on whether voters want a strong mayor--for other people, and more.

Interview with the Chicago Reader's Ben Joravsky on what lies behind the motive to get rid of teachers, and more.

Interview with the Chicago Reader's Ben Joravsky on how Chicago Public Schools handle the re-applications of teachers in turnaround schools, and more.

Interview with the Chicago Reader's Ben Joravsky on how public school students get into particular high schools, and more.

Interview with the Chicago Reader's Ben Joravsky on why using tax-increment financing to build new schools works against the school system's interests, and more.

Interview with the Chicago Reader's Ben Joravsky on why charter schools' ability to get rid of troublesome kids invalidates comparisons with non-charters, and more.

Interview with the Chicago Reader's Ben Joravsky about the difference between magnet, charter, and selective-enrollment schools, and more.

Rahm Emanuel credits charter schools, but based on what?

Rahm Emanuel's declaration about the best-performing high schools turns out to be a lightning rod—though not necessarily attracting the folks you'd expect, like the Chicago press.

It did raise the hackles of charter opponents like Don Moore of Designs for Change. According to Moore, Emanuel implies that charters have good results across the board. But no matter how you manipulate school performance data, that doesn't ring true—especially Emanuel's "seven best performing schools" remark: "No way," says Moore, "that you can make it work."

That didn't stop me from trying.

On the CPS Web site, for example, I found measures of high-school student test-score gains from freshman to junior year.

Using this criterion (taking a composite of English, reading, math, and science scores), five of the ten top-scoring Chicago public high schools are charters. Nine of the ten limit their enrollment; the tenth school is what CPS calls a "neighborhood" school: it must take all comers.

So which data did Emanuel use?

As I reported elsewhere, Emanuel spokesman Ben LaBolt sent me a spreadsheet that ranks schools by "scores" (with Northside on top with 100).

I tried comparing Emanuel's spreadsheet to CPS data on-line—making myself dizzy—but I couldn't find any data that had scores matching the ones LaBolt sent me.

When I asked which data set the campaign used, the campaign said the data came from a spreadsheet on another CPS Web page—but neither that set of data nor the earlier one seems to jibe completely with Emanuel's remark.

It's been pointed out to me that one could find a way to manipulate school-performance data to support just about any charter claim, including Emanuel's. I couldn't, though—which I guess is the point.

No wonder that Emanuel's claim didn't get reported by Chicago's major news-media types.

Then I talked to a few of them—off the record, as they insisted. So while I can't reveal details, they don't seem daunted by the data.

For his part, spokesman LaBolt was anything but adamant about Emanuel's charter remark. "Our policy's not even based on it," LaBolt told me. "If you've got better data, we're happy to use it."

Reporters: Remember that come May.

Interview with the Chicago Reader's Ben Joravsky on tax-increment financing's cloak of invisibility, and more.

Interview with the Chicago Reader's Ben Joravsky on how local school councils came about, and more.

WBEZ's Linda Lutton and Catalyst Chicago's Sara Karp how examine whether Chicago charter schools eject certain poor-performing or behavior-challenged students.

In her first teaching job out of college, Griselda Canas taught for three-and-a-half years at a west-side elementary public school. Canas, who has a master's degree in curriculum and instruction and a bilingual certification, got fired by Chicago Public Schools from her job last August—about a month before she would have received the protection of tenure. Since then, she's learned that she'd been secretly blacklisted: She can never teach in a Chicago public school again.

In the summer of 2010 the CPS administration laid off over 1,300 teachers. When some applied for new teaching positions within CPS, they found that someone had secretly changed their personnel records—preventing them from ever teaching again in Chicago public schools, and maybe elsewhere.

Interview with the Chicago Reader's Ben Joravsky on why the Chicago Public Schools administration would authorize a contract violation, and more.

Interview with the Chicago Reader's Ben Joravsky on whether teachers and students should sacrifice for administrative largesse, and more.