On an overview of on-line education (in the USA)

Brainstorm - Is It Time to Get on Board With Online Education? - The Chronicle of Higher Education

The U.S. Department of Education has conducted a meta-analysis of the effectiveness of on-line education. (For those not familiar with the jargon "K-12" refers to compulsory education [Kindergarten to 12th Grade]).

The picture is far from as clear as advocates of on-line systems claim, but it is an important start.