For Teresa Saathoff, the decision on whether to send her 11-year-old son, Henry, to their neighborhood middle school is coming a year too early.

The grade span at Calverton Elementary, where Henry is a fifth-grader, used to be kindergarten through sixth. But Prince George’s County school officials decided to move the sixth grade to middle school to alleviate crowding. That means Henry will go to Martin Luther King Jr. Middle School next year instead of remaining at Calverton.

King is the only Prince George’s middle school that met federal benchmarks this year under the No Child Left Behind law, but Saathoff is concerned that Henry isn’t ready for the middle school environment.

“He might get exposed to things that I think he’s not ready for,’’ said Saathoff, who would prefer he stay at Calverton, even though it is 27 percent over capacity. “So we’re deciding what to do. The middle schools here have a lot of trouble, so we’re thinking of just sending him to a private school. We didn’t want to make this decision yet.”

This month, parents throughout Prince George’s have been echoing Saathoff’s fears. School officials toured the county to discuss adding sixth grade to more of the county’s middle schools.

Last school year, 11 of Prince George’s 24 middle schools had only seventh and eighth grades. This school year, that number was reduced to nine. Over the next few years, it is likely that the number will continue to decrease.

Perks beyond saving space

School officials said that in addition to helping ease crowding, there are academic advantages to moving sixth grade to middle school.

“This is a very important age, and as students get older you want them to have more options,” said A. Duane Arbogast, the county’s chief academic officer. “The change will make programming easier. In middle school, they’ll have more options for foreign languages, electives. These [choices] are valuable.”

The school configuration changes are among many taking place in the state’s second-largest school system. School officials are considering redrawing attendance zones and transportation routes. State lawmakers are redrawing the district boundaries for school board seats to reflect the county’s growing Hispanic population.

And Prince George’s isn’t the only school system studying grade placement. Researchers, school officials and parents around the country are trying to determine the best way to boost performance among middle-schoolers, who as a group tend to score lower on standardized tests and have more disciplinary problems than those in elementary school.

In Montgomery County, the overwhelming majority of middle schools are grades 6 through 8, the most prevalent path in the nation. Most Fairfax County middle schools have grades 7 and 8. In the District, many parents have expressed concern about the city’s middle schools, arguing that the quality of education varies widely from school to school. The District has experimented with K-8 schools, which have proved popular even though they haven’t appeared to improve academic achievement.

Best setup for learning?

So what’s the best configuration for learning during those tumultuous preteen years? No one really knows.

In Prince George’s, Arbogast points to a paper published by the American Educational Research Association that contends expanding middle school by a grade will produce better results, although its researchers say there are no statistically significant differences in performance unless the middle school grade span is broadened to include fifth grade.

Jonah Rockoff, a professor at Columbia University who studies school configurations, has produced research arguing against middle school completely.

“The earlier students transition from elementary school, the worse it is for them,” said Rockoff, who advocates the K-8 configuration for optimal learning. “That’s the bottom line.”

Prince George’s has a handful of K-8 programs, mostly through its Montessori schools. Adding more K-8 programs isn’t practical, officials said, because elementary schools are already too crowded and the district’s middle schools are underenrolled.

According to data provided by the school system, 38 of the county’s 128 elementary schools exceed the state-recommended student capacity. Only two middle schools exceed those guidelines.

Some parents say there’s a reason for that. Eileen Collins, whose son attends Laurel Elementary School, is concerned when she examines the data: Only one middle school in the county met its academic benchmarks this year.

Collins thinks her son is getting a good education at Laurel, despite the fact that the school is 19 percent over capacity.

She and her husband have been debating whether to send their son to a private school to avoid the county’s middle schools.

“I don’t understand why they would want to fix something that’s not broken,” Collins said. “Middle schools in general are kind of the black hole. I believe that the staff in Prince George’s is really committed to making sure our kids get a great education. But . . . do I want to put my child somewhere that’s a work in progress, in some place where the test scores aren’t as good? It’s hard to accept.”