As companies compete to digitize the textbook market, there is one approach that shakes the traditional publishing business model: open source textbooks, whose proponents believe online educational tomes should be free.

Many universities, including MIT and Carnegie Mellon, post course lectures online for free use. A New York Times article last year explained some of the barriers to applying the same approach to textbooks.

For one thing, the textbook authors must agree to have them distributed online without charging royalties — something that may work well in the software world, where engineers often work on projects while keeping a day job, but typically avoided by writers who put their sweat equity into one book at a time. Also, books for K-12 classrooms must meet state standards, and most states don't have procedures in place for approving open source textbooks.

But there's no arguing that having at least a few open source textbooks (even when purchased through companies like Flat World Knowledge that charge for downloading or printing them) would cut down on the average $900 per year that the average student spends on textbooks. Online School has compiled this infographic to explain the cost savings.

[Source: onlineschools.org]