KANSAS CITY — Missouri's high school graduation rates aren't looking as hot since the state switched to a new federally mandated formula for calculating the statistic.
The change hit close to home, knocking Columbia Public Schools graduation rates down as well.
Numbers released Monday show the state had a 79.8 percent graduation rate in 2011, down 6.6 percentage points from the graduation rate the old formula produced for the same year.
In a release Monday, the Columbia district reported that preliminary results indicate its graduation rate fell to 82.7 percent under the new formula in 2011, down 4.7 percentage points from the old formula this year.
The change statewide was even more dramatic among poor and minority students. Black students, for instance, graduated at a rate of 63.9 percent under the new formula, compared to a rate of 75.1 percent under the old formula.
In the past, states used a variety of formulas that produced wildly different results. Starting this year, most states were required to move to the uniform calculation that requires them to track each student individually, giving a more accurate count of how many actually finish high school.
The new formula essentially takes the number of graduates in a given year, divided by the number of students who enrolled four years earlier. Students who transfer don't hurt a school's graduation rate, but there must be documentation.
"I do think it's an important rate because it allows us to compare ourselves to other states in a more comparable way, and we are looking to see which percentage of our kids graduate in four years," said Leigh Ann Grant-Engle, assistant commissioner for the Missouri Department of Elementary and Secondary Education.
While making the switch, some states have reported graduation rates that are 10 percentage points to 15 percentage points lower than with earlier methods.
In the past, Missouri and half the other states used a calculation called the "leaver method," which has gained a reputation for being the most generous.
The method works like this: If a school had 100 graduates and 10 students who dropped out from their freshmen to senior year, 100 would be divided by 110, giving the school a graduation rate of 90.9 percent.
One reason the "leaver method" tended to produce higher graduation rates than the new calculation method is that it didn't ding schools if students took more than four years to graduate.
To make sure it gets credit for students who need extra time to finish their schooling, Missouri plans to track its five-year graduation rate separately. That number won't be available until next year.
"There are many students that it is appropriate for them to take longer than four years possibly for them to graduate," Grant-Engle said.
Missourian reporter Zach Murdock contributed to this article.