I LEARNED many fascinating things while taking a series of free online college courses over the last few months. In my history class, I learned there was a Japanese political plot to assassinate Charlie Chaplin in 1932. In my genetics class, I learned that the ability to wiggle our ears is a holdover from animal ancestors who could shift the direction of their hearing organs.

But the first thing I learned? When it comes to Massive Open Online Courses, like those offered by Coursera, Udacity and edX, you can forget about the Socratic method.

The professor is, in most cases, out of students’ reach, only slightly more accessible than the pope or Thomas Pynchon. Several of my Coursera courses begin by warning students not to e-mail the professor. We are told not to “friend” the professor on Facebook. If you happen to see the professor on the street, avoid all eye contact (well, that last one is more implied than stated). There are, after all, often tens of thousands of students and just one top instructor.

Perhaps my modern history professor, Philip D. Zelikow, of the University of Virginia, put it best in his course introduction, explaining that his class would be a series of “conversations in which we’re going to talk about this course one to one” — except that one side (the student’s) doesn’t “get to talk back directly.” I’m not sure this fits the traditional definition of a conversation.