Shortly before he left office at the end of 2010, Sonny Perdue flew around the state holding several news conferences to take credit for an alleged increase in Georgia’s high school graduation rate during his two terms as governor.

Perdue claimed that the graduation rate had been only 63 percent when he took office in 2003, but thanks to his efforts that rate had increased to nearly 81 percent for 2010. People who actually knew something about statistics and public education never took the governor’s claim seriously.

A report released by Education Week several months before that grand tour indicated Georgia was one of five states with a graduation rate below 60 percent. An earlier analysis conducted for Georgia’s Board of Regents found that the graduation rate was only 55 percent and had dropped by eight percentage points from 1990.

It was all an empty boast from a governor who cut Georgia’s funding for public education by a larger amount than any governor in recent memory. Perdue and the state school superintendent during much of his administration, Kathy Cox, cited numbers derived from a flawed formula known as the “leaver rate.” That formula tended to inflate the percentage of students who were supposedly receiving a high school diploma within four years of entering the ninth grade.

Education experts knew that a more accurate accounting of the graduation rate was going to be released in the months after Perdue left office. The federal education department was in the process of requiring all states to convert to a more rigorous formula known as the “cohort rate” that would provide a more credible and accurate measurement of graduation rates.

To his credit, the new state school superintendent, John Barge, did not try to fool people with inflated numbers when he took office in 2011. From the very first, Barge cautioned educators that the new formula would cause the graduation rate to drop by as much as 15 points. The state Department of Education last week released the first set of graduation numbers calculated under the new formula. It turned out that our graduation rate was far lower than some officials had been claiming.

Using the same formula that all other states are now required to employ, the education department said Georgia’s graduation rate was just 58.6 percent in 2009, although it improved a little to 64 percent in 2010 and 67.4 percent in 2011.

None of those numbers are anywhere close to the 81 percent that Perdue was bragging about just 18 months ago. Is that reduction in the graduation rate disappointing? Of course it is. But at least the education department is finally leveling with the parents and students whose interests it is supposed to serve.

“I believe that in order to tackle a problem, you have to have honest and accurate data,” Barge said when the revised numbers were released. “We will be able to use this new data as a baseline to see how our important initiatives are impacting graduation rates in the future.”

The important point, education officials contend, is that Georgia finally is using a credible formula that will make it possible to get a more consistent accounting of how public schools are performing.

“No method of calculating it is perfect,” said Herb Garrett of the Georgia School Superintendents Association. “They all have their flaws. But at least everybody’s on the same footing.”

As we have seen with the inflated graduation rates and the recent test cheating scandals in the Atlanta and Dougherty County systems, there is too often a tendency for public officials to cook the numbers in an attempt to hoodwink the public.

I hope the release of more accurate graduation numbers is a sign that the trend is on the way out.

Tom Crawford [email protected]

Tom Crawford is editor of The Georgia Report, an Internet news service at gareport.com that reports on government and politics in Georgia.