Whenever people imagine virtual anything, they immediately pit it against its physical counterpart—Amazon versus physical book stores, Wikipedia versus physical encyclopedias. They assume that the virtual will replace the physical with something cheaper, faster and more efficient. In education, however, the virtual will create a very different type of disruption. We should not aim to replace the physical classroom. Instead we have an opportunity to blend the virtual with the physical and reimagine education entirely.

Today students in most classrooms sit, listen and take notes while a professor lectures. Despite there being anywhere from 20 to 300 human beings in the room, there is little to no human interaction. Exams often offer the first opportunity for the professor to get real information on how well the students digested the knowledge. If the test identifies gaps in students' understanding of a basic concept, the class still moves on to a more advanced concept.

Virtual tools are providing an opportunity to rethink this methodology. If a lecture is available online, class time can be freed for discussion, peer tutoring or professor-led exploration. If a lecture is removed from class time and we have on-demand adaptive exercises and diagnostics, there is no need to continue the factory model inherited from 19th-century Prussia—where students are pushed together at a set tempo. Instead students can progress at their own pace and continue to prove their knowledge long after the formal course is over.

Over the next 10 to 20 years blended learning will also allow us to decouple credentials from learning—today both these functions are done by the same institutions. This approach will allow anyone to prove that they have mastered a set of skills at a high level, whether they learned them on the job, at a physical school, through an online resource or, most likely, all of the above.

Perhaps the most powerful effect of this reality is what it does to the quality of lectures and other learning material in general. Traditional lecturers and textbook publishers have little to no information on how their content is being used or whether it is even effective. By coupling rich physical experiences with online tools, content creators and professors can finally have granular, up-to-date data on the efficacy of the experiences they create.

In this “blended learning” reality, the professors' role is moved up the value chain. Rather than spending the bulk of their time lecturing, writing exams and grading them, they can now interact with their students. Rather than enforcing a sit-and-listen passivity, teachers will mentor and challenge their students to take control of their own learning—the most important skill of all. Yes, for a motivated student in an impoverished part of the world, these virtual tools—assuming we can overcome accessibility issues—may facilitate most of their learning. In the developed world, the best experience will be to leverage the online tools so that the physical time can be less passive and more, well, human.

Read an interview with Khan at ScientificAmerican.com/aug2013/khan