Georgia’s school grading scale is “tougher” than those in other states, says a new study that is timely given Gov. Nathan Deal’s announcement Friday that he plans to focus on fixing failing schools during this legislative session.

In November, voters rejected Deal's pitch for an Opportunity School District that would have allowed him to take over "chronically failing" schools, and on Friday he told The Atlanta Journal-Constitution that he isn't giving up. Indeed, he said he'll focus on the issue during the upcoming legislative session, likely to the exclusion of other educational measures, such as a rewrite of the state's school funding formula.

The details of his plans haven’t been released, but it will likely hinge on the school grading system developed by law, another state agency and officials who report to him.

The Georgia Department of Education was mandated by law to create the College and Career Ready Performance Index (CCRPI), a complex 110-point scoring system based largely on standardized state test results. But the Governor’s Office of Student Achievement assigns an “A-F” grade to each school, based on those underlying scores.

Martha Ann Todd, the GOSA executive director, described the grades and associated information on her agency's website as "parent-friendly, concise reports," but the state's largest teacher organization, the Professional Association of Georgia Educators, says they lack helpful information.

That grading scale is also apparently harsher than scales employed in the handful of other states with similar measurement systems.

An assistant professor at the University of Georgia looked at the school grades against the underlying CCRPI scores and compared the translation to grading scales in Florida, Louisiana and Massachusetts, finding that Georgia sets a higher threshold.

For instance, to get a “D,” Georgia schools must earn at least 54 percent of the available CCRPI points while Florida and Louisiana give the same grade to schools that earn 32 percent and 33 percent respectively on their own school indexes.

Massachusetts, a high-performing state, uses a numerical rather than letter grade but the report says it’s basically less stringent than Georgia’s.

“Overall, it appears that Georgia has a tougher grading scale than other Southeastern and high-performing states,” wrote the report’s author, Richard O. Welsh.

He also found a strong correlation between low CCRPI scores and poverty. And schools with more black than white students tended to earn low scores.

The measures are important because they are used to identify the “chronically failing” schools that could be singled out for the governor’s special attention.

Todd said her agency decided a score below 60 should merit a failing grade because that and the other cut scores in her letter grade scale “mirror the scale that parents and stakeholders are most familiar with in terms of grading.” She added that Georgia’s tougher scale is “perhaps more appropriately viewed as setting high expectations” for the education system.

On Thursday,  Todd's agency released a new list of schools that have earned an "F" for three years running -- that's the definition of chronically failing -- and it grew, from 127 to 153.

Lawmakers from both the state House and Senate said fixing failing schools is a priority for them.

State Superintendent Richard Woods, whose agency produces the CCRPI, has read the UGA study and he agreed with the findings, saying the state needs to do a better job of crediting schools that are able to show student improvement, even if their test scores are relatively low. He can change some things on his own, but crucial elements of the CCRPI are written into law, so any change will require lawmakers’ involvement. And, of course, he has no control over the A-F letter grades assigned by GOSA.

“I think we have to look at something that is fair” to schools, Woods said. “Because with the metric that is being used we are not giving them hope.”

Todd agreed with Woods on at least one key point: Schools should get more credit if they are able to improve students’ performances. She said her agency will advocate for that and other changes as Georgia amends its CCRPI to comply with new federal education policy.