First-grader Isabella Watkins is soaring academically at Decatur’s Oakhurst Elementary. Her dad, Steve Watkins, says that’s most likely because of Isabella’s positive Georgia pre-kindergarten experience.

Teachers in the lottery-funded program for 4-year-olds taught Isabella everything from letter sounds and vocabulary to proper handwashing skills and consideration for her classmates.

But more importantly, she “learned how to be a student,” said Watkins, a retired firefighter.

A new and first-of-its-kind study shows students such as Isabella are leaving Georgia’s voluntary pre-k program with a leg up on other 4-year-olds. However, pre-k classes still largely fall short of meeting the highest standards for quality, according to researchers at the University of North Carolina’s Frank Porter Graham Child Development Institute.

In the 2011-2012 school year, the researchers observed a random sample of 100 of Georgia’s 3,922 pre-k classes and analyzed assessments of the developmental skills of 509 of their students, coming away with two recommendations: Increase bilingual support for dual-language learners and reduce class sizes.

In a draft report on their work, they said Georgia youngsters show “significant growth” during their pre-k year in all areas of learning, including vocabulary, word and letter identification, behavioral skills and math skills, such as counting.

UNC researchers saw across-the-board gains among pre-k students, regardless of gender or family income.

In terms of classroom quality, they found instructional support had improved since a 2008-2009 study that motivated the push for quality improvement.

But the researchers also found that 20 years and $5 billion after the program was started, the vast majority of Georgia pre-k classes (85 percent) are medium quality, not high quality.

On average, pre-k classes scored lower on measures of global classroom quality, such as materials, and slightly lower on teacher-child interactions, such as emotional support, the draft report said. Only 2 percent of classrooms were rated high quality, and 13 percent were low quality, the researchers said.

Some experts say that’s not surprising, given recent budget cuts resulting in larger classes, a 20-day cut in the pre-k year and a mass exodus of mostly experienced teachers.

“You might say it’s a testament to the teachers that they have maintained (medium quality),” said Pat Willis, executive director of the advocacy group Voices for Georgia’s Children. “You have to be careful judging a lack of change in a period where we’ve put a lot of stress on these classrooms.”

“When we looked at it, compared to across the country and the District of Columbia, there were only a couple of states that had class sizes worse than Georgia,” said Ellen Peisner-Feinberg, the study’s chief author and a senior scientist at FPG Child Development Institute. “When you have fewer children in the classroom, fewer children per adult, it’s actually easier for teachers to do what we’re asking.”

Georgia became known as a national leader in early childhood education when, under former Gov. Zell Miller, voters passed a state lottery and dedicated a sizable share of the revenues to creating a voluntary pre-kindergarten program.

The program, which is expected to be back to 180 days a year by next fall, has enrolled about 1.2 million 4-year-olds and routinely has several thousand others on waiting lists. It still ranks as one of the nation’s most highly regarded pre-k programs, although as lottery revenues have flattened there’s been more pressure for studies of its longterm impact on student learning.

The UNC study is costing $1.5 million in lottery dollars and will include a second phase tracking students who went through the program in 2011-2012 against a future class of pre-k students, said Bobby Cagle, who oversees pre-k as commissioner of Bright From the Start: Georgia Department of Early Care and Learning.

Andy Hooper, a father of two from the Briarlake area of DeKalb County, had a daughter in pre-k last year and saw how it helped motivate her in reading. “While we tend to focus on reading here in the home, we thought it was very beneficial … to, in a classroom setting, have the concepts drilled into her about sounding out words.”

Kelsey Miller, a pre-k teacher at Kemp Primary School in Clayton County, said the program can be transformational, both academically and socially, for 4-year-olds, some of whom have never been in a classroom setting before. They leave pre-k “with the core things under their belt,” she said.

Tonya Pugh, a first-grade teacher at Kemp, said pre-k’s biggest advantage is that it exposes the students “to learning and to being curious about what’s around them.”

“When they get to me, they are very well-equipped with the necessary skills,” Pugh said.

Carolyn Salvador, executive director of the Georgia Child Care Association, said the study shows “children are learning, and we are achieving school readiness.”

She said she was particularly glad to see gains made within the bilingual communities. “They are gaining a solid foundation with a trajectory to be successful later in life.”

But economic realities likely had a bearing on the report’s finding that pre-k is not moving the needle toward higher quality, Salvador said.

“By and large, (pre-k) providers are dealing with economic issues that are outside of their control that impact the quality of the environmental setting, which is what part of this study is measuring,” she said.

Connie Moore, director of the nationally accredited Suburban Nursery School in Decatur — who has one class of 22 pre-k students — said quality has to be the major focus, whether the issue is classroom materials or healthy food options for the students.

“We pour our hearts into it,” Moore said.