Despite Connecticut students’ above average-performance on math and reading, the state continues to face the widest achievement gap in the nation, according to National Assessment for Educational Progress (NAEP) data released by the U.S. Department of Education last week.

NAEP, a test administered every two years to fourth- and eighth-grade students nationwide, assesses students’ abilities in math and reading and measures disparities between students of different racial and socioeconomic groups. Overall, the percentage of Connecticut students at or above proficiency in both fourth- and eighth-grade math and reading levels is higher than the national average, but the state maintains a stark achievement gap between low- and high-income students and between white and minority students, the report shows.

According to data analysis by the education nonprofit ConnCAN, the NAEP results show that Connecticut ranks worst in six of 16 categories that measure the achievement gap. The categories compared low-income vs. non-low-income, African-American vs. white, Hispanic vs. white and English language speakers vs. non-English language speakers, across fourth- and eighth-grade math and reading scores.

“When you look at it holistically, Connecticut is failing to provide high-quality education to low-income, black and Hispanic students, and that is simply unacceptable,” ConnCAN Communications Director Brett Broesder said.

Broesder explained that while white students and non-low-income students are relatively strong in reading and math, low-income students — especially those from minority groups — are lagging behind their peers in other states.

This persistent achievement gap in Connecticut is tied to the state’s income disparities, Director of Yale’s Education Studies Program Elizabeth Carroll wrote in a Wednesday email to the News.

This divide is evident in Greater New Haven, where only 17 percent of low-income students are reading at grade level whereas 58 percent of high-income students are meeting standards, a recent DataHaven report shows.

According to the 2010 census, Fairfield County is the nation’s most unequal county in terms of median household income. Carroll said the quality of public schools that children have access to is directly related to neighborhood affluence, with the wealthier suburbs having more highly funded schools.

But while the NAEP results show where states like Connecticut stand in terms of math and reading levels, they do not directly illustrate how to best improve education systems.

“I recommend that we use results like these to find states and districts where historically underprivileged groups are making sustained, significant progress and then start the difficult work of more systematic evaluation research to try and identify what really works and why,” Commissioner of the National Center for Education Statistics Jack Buckley said in an email to the News.

The report found that certain states, including Tennessee and Washington, D.C., did make significant improvements in overall math and reading scores since 2011. Broesder said that the improvements in both Tennessee and Washington stem from education reform initiatives that are similar to those launched in Connecticut in 2012.

Tennessee raised its education standards in 2009 and in 2011, adopted professional teacher evaluations that assess teachers based on student performance and provide teachers with support and guidance to strengthen instructional practices. Washington, D.C. similarly adopted IMPACT, a program that evaluates teachers’ strengths and weaknesses and provides assistance to struggling teachers. Both states also adopted the rigorous Common Core State Standards in 2010 and have put resources toward school turnaround and expanding charter programs.

In 2012, Connecticut launched a comprehensive education reform program, which includes state oversight of turnaround schools, a teacher evaluation system and increased support for charter schools. Through the Commissioner’s Network school program, the State Department of Education has offered additional resources and strategies to improve 11 unsuccessful schools, two of which are in New Haven.

Because Connecticut’s reform initiative is still in its early stages, Broesder said, there has not been enough time to see real improvements in scores on the NAEP.

Still, Broesder said that if the state continues to allocate resources toward increasing access to high-quality public schools, improving low-performing schools and establishing stronger teacher evaluation systems, Connecticut will ultimately see increasing scores and a narrowing achievement gap.

“When states put in the effort to improve schools, kids are making gains regardless of race or ZIP code,” Broesder said. “We are making good progress, but to close that worst-in-the-nation achievement gap, we need to keep pressing for all kids to have access to high quality education.”

The NAEP data is based on the scores of over 376,000 fourth-graders and 341,000 eighth-graders.