This is the VOA Special English Education Report.

Each new school year brings fresh reminders of what educators call the summer learning gap. Some call it the summer learning setback. Put simply, it means the longer kids are out of school, the more they forget.

Some schools let students take summer classes online. Scott Landry, 14, of Massachusetts did that last summer.

The only thing they might gain is weight. Recent studies show that children gain weight more quickly in the summer than when they are in school.

Most American schools follow a traditional nine-month calendar. Students get winter and spring breaks and about ten weeks of summer vacation.

Some schools follow a year-round calendar. They hold classes for about eight weeks at a time, with a few weeks off in between. The National Association for Year-Round Education says there were fewer than three thousand such schools at last count. They were spread among forty-six of the fifty states.

But many experts point out that the number of class days in a year-round school is generally the same as in a traditional school.

Brenda McLaughlin is research director at the National Center for Summer Learning at Johns Hopkins University. She says studies of year-round schooling have not found strong learning gains.

Last year, a study at Ohio State University reported that year-round students did not learn any more than other students. Lead researcher Paul von Hippel said "year-round schools don't really solve the problem of the summer learning setback. They simply spread it out across the year."

Across the country, research shows that students from poor families fall farther behind over the summer than other students. Experts say this can be prevented. They note that many schools and local governments offer programs that can help.

But calling them "summer school" could be a problem. The director of the summer learning center at Johns Hopkins, Ron Fairchild, recently wrote about this issue on his blog.

He said that in American culture, the idea of summer vacation is connected to beliefs about freedom and the joys of childhood. He said research with groups of different parents in Chicago and Baltimore found that almost all strongly disliked the term summer school. They said it created an image of children being forced to do work they missed during the school year.

The parents welcomed other terms like "summer camp," "enrichment," "extra time" and "hands-on learning."

And that's the VOA Special English Education Report, written by Nancy Steinbach. Join us Monday for a back-to-school report on THIS IS AMERICA. I'm Jim Tedder.