AA: I really believe that online learning, and virtual education is another tool in our arsenal. What tools have we given teachers for the past 500 years? We’ve given teachers chalk, blackboards, textbooks, and dare I say, the PowerPoint. We haven’t given teachers a whole lot of tools. I think clicker technology is a tool that some people have begun to use, but there’s not a whole lot of tools that technology has given teachers. We believe that online learning is another tool in our educational arsenal. I don’t believe that online learning will replace in-person learning. We believe it will augment it. So for the students who do not have access to school, who do not have access to great teachers, it can suffice for giving them an education. But certainly for students who already have access to teachers and access to learning, online learning can improve the quality of their education by creating models in which we combine the best of online learning  and in-person. That is why I like to say that online learning is like a rising tide that will lift all boats—it’ll increase access to those who don’t have access, and will improve learning for those who do have access. It really could help everybody. I really don’t see it as a replacement. I see it as creating another extremely powerful tool in our educational arsenal.

THC: The finding of a set of working papers this spring showed that relatively few people who registered for a HarvardX or MITX a course actually viewed all the chapters—much less received a certificate of completion. In a physical classroom or a lecture-hall setting, seeing these high attrition rates would likely be somewhat shocking to a teacher. Why is edX not held to the same standards that a physical classroom would be?

AA: First of all, I think edX should be held to the same standards as a physical classroom. However, the metric—the completion rate—is not comparing apples to apples. I would like to answer the question in two ways. First, let’s talk about the metric. The metric says that if you have a 100,000 students who registered, all they did was express interest in the course. All they had to do was click on something and they showed up for the course and 6 percent passed the course. So in the denominator, you have students who simply clicked a link expressing interest in taking a course. If you take a course in a classroom, at Harvard and MIT, the pass rate might be upwards of 95 percent. We are comparing that, in the denominator, to students that have registered for the course, and are taking the course for credit.

I used to teach a course on parallel computing at MIT, and it was typical that on the first day of class, 80 students would show up, so people were shopping around for courses. But if you look at the number of students who pass the course in the end it would be on the order of 40 students, but you don’t say the pass rate is 50 percent, so how do we get 96 percent as a pass rate? 80 students showed up as auditors, but of those, only 45 would end up taking the course for credit, of which 42 or 43 students might pass the course. But we don’t count the pass rate as a fraction of the number of people who showed up on the first day of the course.

So I think we need to think about metrics, so a better metric is a pass rate as a fraction of students who signed up for a verified certificate and are paying a small fee. And if you look at the proportion of students who pass the course as a fraction of those who signed up for a verified certificate, it is on the order of 60 percent. So I think we should compared apples to apples.

That said, we do want to improve the completion rate for courses. We want more people to sign up for certificates and we want more people to pass the course once they sign up for a certificate. We’re looking at a number of ways to improve that as well.

—Staff writer Michael V. Rothberg can be reached at mrothberg@college.harvard.edu. Follow him on Twitter @mvrothberg.