I tried an online edX course to better understand the experience. The video lectures and supplemental reading were very good. The online "computer" grading system was terrible and extremely frustrating. There were time when my solution worked locally (computer programming) but failed to pass the computer grader. There was no feedback. My son uses the online problem sets at his school and I find this a very poor excuse for "education." There is no feedback - answers are either right or wrong – there is no learning component. We learn by trying things out, and when we fail, it is important to understand why and what did we not understand. Computer based learning has a way to go (if ever) before fulfilling this aspect of interactive education. Don't take the "human" out of the loop. edX should strive to increase accessibility, but not at the expense of providing the rich learning feedback loop that I believe makes MIT shine!