Four in 10 tweens are interested in taking an online course before graduating from high school, according to a North American Council for Online Learning-commissioned survey conducted by Harris Interactive.

Only 7% of all elementary or secondary students had ever taken an online course.

"Survey results show that many students are interested in taking online courses," said Susan Patrick, CEO of NACOL, in a statement.

Ms. Patrick said that the top reason courses are offered online is that they are otherwise unavailable to the students.

Twenty-six states run state virtual school programs, and 19 allow virtual charter schools or e-schools.

Harris Interactive surveyed 1,183 students between 8 and 18 years olds.