As younger, inexperienced teachers are thrown into classrooms to meet new federal standards, as much as 90 percent of the burden of instruction rests on textbooks, said Frank Wang, a former textbook publisher who left the field to teach mathematics at the University of Oklahoma.

And yet, few if any textbooks are ever subjected to independent field testing of whether they actually help students learn.

“This is where people miss the boat. They don’t realize how important the textbooks are,” Wang said. “We talk about vouchers and more teachers, but education is about the books. That’s where the content is.”