Abel Uribe/Chicago Tribune

Today WBEZ's veteran education reporter, Linda Lutton, has a good piece on a math teacher at Leif Ericson Elementary in East Garfield Park, who's challenging the math behind his school's closing. After it's closed down, CPS plans to move its students to Sumner in West Garfield Park—a school the teacher claims is not even as good as the one that will be shuttered.

CPS, obviously, defends the closing, and it's worth taking a look at how the schools are compared to get a sense of the data being used.

The teacher, Michael Colwell, showed up at the hearings to defend Ericson:

Mr. Colwell expressed concern over the school closing. After researching the decision, he concluded that Ericson is more utilized than Sumner and ranked higher in some performance categories than other schools in the Network and District. He discussed that the enrollment rate has increased more than Sumner. He also described that the test scores at the school are high and better than average. 

Ericson is unquestionably more utilized. According to CPS formulas, Ericson has 510 students compared to an ideal enrollment of 780, or 65 percent utilized. Sumner has 375 students out of 1320, or 28 percent utilized. Sumner students plus Ericson students in the Sumner building equals 885 out of 1320, or 67 percent utilized.

Overall, Colwell's point is that Ericson is a decent school, much better than many CPS schools, and in that his point seems to be reasonably solid. Perhaps more instructive is a comparison to Sumner, where Ericson's students are going. Sumner does outperform Ericson by some metrics, but the difference is not necessarily profound.

Comparative performance: "ranked higher in some performance categories than other schools in the Network and District." Lutton runs the numbers, and that's true as well; Ericson is in the middle of the pack for district schools.

Attendance: "He discussed that the enrollment rate has increased more than Sumner." I don't see a substantial difference in the increase of the attendance rate, but Ericson has had higher attendance than Sumner, according to CPS data, every year over the past decade. Ericson's lowest rate was 94.7 (2008 and 2009), and its high 95.7 (last year). Sumner's low was 91.7 (2005 and 2007), and its high was 94.8 (last year).

Test scores: "He also described that the test scores at the school are high and better than average."

This is where it starts to get tricky.

* Ericson's percentage of students meeting or exceeding ISAT composite scores fell from 74.3 percent in 2011 to 71.8 percent in 2012. The CPS overall average rose from 75.6 to 76.4 percent.

* Sumner's percentage increased from 73.0 percent to 77.2 percent over the same time.

* Over a five-year period, Ericson increased from 60.1 percent to 71.8 percent ; Sumner increased from 72.4 to 77.2. But among the criteria that schools have to meet to avoid closure is "same or higher performance level for SY 2011-12 as SY 2010-11."

* Another criterion is "Students are performing at or above their peers in reading or math for each of the last 3 years." Ericson students have underperformed their CPS peers overall in reading the past three years, by as little as 3.8 points and as much as 9.3 points. In math, Ericson students have outperformed their CPS peers in the past two years after taking a big leap (13.5 points) in 2011.

* But Ericson is 95.7 percent low income and 97.6 percent black (Sumner is 89.2 percent low income and 96.1 percent black).

* In terms of black students throughout CPS, Ericson students outperformed their peers in reading two of the past three years. In math, Ericson students outperformed their peers two of the past three years.

* CPS free-lunch students outperformed Ericson students each of the three years in reading. Ericson students outperformed their peers in math two of the past three years.

* Sumner? Overall its students underperformed CPS in reading two of the past three years; in math, one of the past three years.

* Sumner's black students outperformed CPS's black students all three years in reading; in math, all three years.

* Sumner's free lunch students outperformed CPS's free lunch students two of the past three years in reading; in math, two of the past three.

If you look at Ericson's page on Schoolcuts.org, you'll find nearby schools with lower utilization and performance scores, like Herzl, which is 38 percent utilized with seven percent of the possible performance points, compared to 65 percent and 45 percent for Ericson. According to Lutton, Colwell plans to go to Springfield to plead his case.

His numbers—as you might hope for an elementary math teacher—make a compelling case.