Enrollment in online classes last year reached the 1 million mark, growing 22 times the level seen in 2000, according to the North American Council for Online Learning. That's just the start, says a new paper by the Hoover Institute, a conservative think tank at Stanford University. Its authors predict that by 2019 half of courses in Grades 9 to 12 will be delivered online. The efficiency of online learning accounts for this growth. But there's little research assessing the quality of these programs, which some experts say don't have enough official oversight.

Under the federal No Child Left Behind law, "you have to have high standards, tight oversight, scrutiny over what teachers are doing. Yet on the other extreme, also promoted by the federal government, are these loosely accountable approaches to schooling," says Luis Huerta, a professor at Columbia University's Teachers College who has researched virtual schools for more than a decade.

There's also debate over how much public funds go to virtual schools. Dr. Huerta's research revealed school districts that championed new virtual charter schools to collect per-pupil funding for students who cost less to educate.

Published Tuesday, Oct. 21, 2008