Years ago, I was telling the fourth grade class I taught in New York City about the problem of summer loss. One little girl, normally quiet and shy, voiced a reaction that I’ll never forget.

“Summer school?” she said. “Mr. Boulay, that is evil.”

As the interim CEO of the National Summer Learning Association, I usually get a laugh when I recount this story – the kind of laugh that implies recognition. Today’s adults are likely to have vivid, negative memories of summer school, but those memories and images are causing an enduring problem for today’s kids. For the real evil is not summer learning, but the lack of it.

A century’s worth of research has affirmed that summers without learning cause most children to lose several months’ worth of the academic skills they’ve gained during the school year. These losses are particularly acute for low-income children, who fall several months behind their higher-income peers in reading each summer. By ninth grade, a Johns Hopkins University study found, these children were more than three years behind their peers in reading, an achievement gap due in large part to unequal summer learning opportunities. The lower-income children in the study who had fallen behind in summer also were less likely than their better-off counterparts to graduate from high school and to pursue college.

The remedial, punitive history of summer school hasn’t helped solve this drag on student achievement. It’s also true that everyone needs vacations, breaks, and changes of scenery. But why does vacation have to mean vacuum? Why can’t relaxation include the creative learning that children actually crave? Who says summer learning needs to look like school-year education?

In fact, summer is the perfect time for kids to learn differently and teachers to teach differently, to do projects that take advantage of the summer weather and harness the season’s spirit of possibility.

That’s the way it happens in families with means and opportunity. Those parents send children to camps that explore their passions - to ride horses, appear in plays, or study robotics. The family might take a vacation to a national park or a Civil War battlefield. In all of these scenarios, children are learning without anyone calling it “school” – and they’re having a great time. For low-income children, by contrast, a summer without learning is likely a time with limited options, a time when it may not even be safe to play outside or walk to the library.

Public school districts such as Cincinnati, Pittsburgh, Baltimore, and Oakland, Calif., have recognized the need to design a new kind of summer school that offers enough hours to make a real difference in outcomes and enough choice in activities to interest children at all kinds of learning levels, not just those who need to catch up.

Baltimore’s “Grand Prix of Summer Learning,” for example, sounds anything but dreary. Offerings include soapbox car-building, swimming with instructors from the Michael Phelps Swim School, and learning math through rhythmic dance. The National Summer Learning Association has embarked on a three-year project with the Walmart Foundation to provide 20,000 new summer learning opportunities for middle schoolers by bringing large urban school districts together with high-quality programs that provide a full slate of integrated academics, enrichment, and physical activity. The programs also have the important role of providing summer meals for children when school lunches are not available.

These creative approaches to summer school don’t mean that children will need to give up summer activities with their parents or at their favorite camp. They do mean that more children will have more affordable options - not just for an enjoyable summer, but one that literally helps them grow.

I like to think that my long-ago fourth-grade student, now all grown up, would look at these offerings and say, “Summer school? Mr. Boulay, that is good.”

Our challenge now is to replicate these successful models of summer learning in many more school districts. A recent report from the RAND Corporation found that while effective summer learning programs can prevent summer learning loss and even boost student achievement, many district officials are reluctant to spend the money on them in tight budget times. School systems today are certainly faced with tough financial choices. But the research shows that, designed correctly, summer learning programs can be worth far more than they cost when it comes to leveling the educational playing field.

Matthew Boulay is interim CEO of the National Summer Learning Association in Baltimore, Md.

All statements and opinions expressed on this blog are those of the individual contributors, and not of the Bill & Melinda Gates Foundation or NBC News.