Illinois High School Graduation Rates Plummet Under New Federal Formula (VIDEO)

On Monday, Illinois released report cards for each of the state's schools under a new formula bringing the way it reports school graduation rates in line with federal directives.

As a result, about 75 percent of high schools saw their graduation rates decline, some dramatically, the Chicago Tribune reports. The new formula calculates schools' graduation rates by tracking a cohort of individual students, while also requiring students to graduate in four years.

(Click here to view school-by-school test scores and graduation rates.)

High school graduation rates are considered to be one of the most significant measures of educational success. A 2009 study conducted by the Consortium on Chicago School Research at the University of Chicago, referenced by the Tribune, reported that "high school graduation is a strong indicator of social and economic well-being." The same report also noted that the calculation of graduation rate is a complicated matter that lacks a flawless method.

U.S. Education Secretary and former Chicago Public Schools head Arne Duncan previously lauded the new, somewhat controversial formula as "simply being more honest," while others have argued that some students take a longer time to graduation and should not be punished for that.

While most schools nationwide are required to adopt the new formula in calculating and reporting their graduation rates, the number will not count toward their No Child Left Behind benchmarks until the 2012-13 school year.

Not all schools have seen their graduation rates fall under the new formula, however. At Chicago's Douglass Academy High School, where Principal Debra Crump has been known to go as far as tracking down absent students by showing up at their homes and knocking on their doors, the graduation rate has rocketed from 48.3 percent in 2010 to 89.8 percent this year.

The report also revealed that average scores on an important third-grade reading exam are also down: more than one-fourth of all students failed the reading portion of the Illinois Standards Achievement Test. Last week, the Illinois State Board of Education launched an investigation into 33 schools in the state, including nine in Chicago, whose ISAT scores showed "irregularities" which could require discipline.

Many of the highest-performing schools have school days longer than is typical for Chicago public schools, according to a Chicago Sun-Times analysis of the new report, lending some support to Mayor Rahm Emanuel and CPS head Jean-Claude Brizard's continued push for the longer day systemwide. It should be noted, though, that many of the highest-ranking schools are located in affluent suburban districts.

Further, as WBEZ warns, many researchers argue that the way the state reports their school-by-school report cards is at least somewhat misleading and inaccurate.

WATCH an interview with Brizard, featuring his response to the disappointing graduation rates both in Chicago and statewide:

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