Technology in teaching

From Swans on Tea:

Education is not an industry that benefits greatly, efficiency-wise, from technology. 

That is, educational efficiency is limited by brains, not computers. Although technology has helped in many areas of education (research, writing, etc.), it has remained flat in terms of actual learning. Why?

If it can’t help the professor teach a class, it’s not going to hold the cost of instruction to the level of inflation.