For the second straight year, Hawai'i's 27 charter schools have kept pace with traditional public schools under the federal No Child Left Behind Act, with 37 percent meeting the state's academic targets.

However, this is a decline of 18 percentage points from last year (a difference of two schools), due in part to significantly higher benchmarks in reading and math that eluded the majority of public schools across the state, regardless of type.

Despite the setback, 13 of the 27 charter schools are still in good standing under the law after last spring's administration of the Hawai'i State Assessment and will remain there if they hit the targets next year.

But an equal number have missed their targets for three years, and another — Kualapu'u on Moloka'i — is now subject to restructuring, the most severe sanction under the federal law.

Charters, which are public schools with their own local school boards, have the flexibility to choose their own curricula and teaching strategies but are bound by the same academic standards as other Department of Education schools.

The first charter school, Wai'alae Elementary, converted in 1995. Lanikai soon followed, and the rest of the schools have opened or converted since 2000.

While charter schools nationally have underperformed compared with regular public schools, for the past two years — the only years they have been treated as their own "district" — Hawai'i's charters have at least kept up with the rest of the state.

Kualapu'u's status presents an interesting case because schools in restructuring could potentially be converted to charter schools under the No Child Left Behind Act.

The small rural school made the decision for itself before reaching the point where it would be forced into action under the law.

"Kualapu'u actually preemptively converted to charter because they knew where they were headed," said Jim Shon, executive director of the Charter School Administrative Office.

However, a year has not been enough time for the school to completely reverse its downward trend, he said.

At this point, there is no clear definition of what restructuring will mean at that or any charter school, but it will be a few years before any other school is threatened with the penalty.

"It's kind of exciting in a sense to have the luxury of one school to sort out what restructuring will mean," Shon said.

Shon does not expect that charters or any other schools will be spared the fate as the No Child Left Behind Act targets get even harder to reach.

"It's an inevitable march of all schools toward restructuring as each year's proficiency ramps up even more," he said.

While the charter school numbers look favorable when compared with traditional schools, their sample size is significantly smaller — 27, compared with 255 traditional schools.

In addition, those with small student-populations may not have to separate out their disadvantaged, disabled or non-native English speakers, which have to reach proficiency on their own if there are 40 or more such students per grade.

DOE spokesman Greg Knudsen offered further cautions against making comparisons between charter and traditional schools, or even considering charter schools as a whole.

"It really takes examination on a school-by-school basis," he said.

In addition, he points out that one reason fewer charters are being sanctioned is that many have not been in existence long enough to even be subject to the more severe penalties.

Shon agrees that considering charters as a whole doesn't work well, considering that there are vast differences between the 27 schools, which include rural and urban schools, Hawaiian immersion schools, Hawaiian culture-based schools, schools that converted from traditional schools and those that started from scratch.

"It's hard to respond to (adequate yearly progress) challenges in any generic way," he said.

Reach Treena Shapiro at tshapiro@honoluluadvertiser.com.