How do you answer the questions of 34,000 students? Well you don't, but we've learned that the community that has formed around our MOOC creates a supportive and interactive learning experience for those students who want to raise their hand and get involved.
The fact is, Silicon Valley has yet to come to terms with education. It's a massive, global market, but a notoriously complex one that is tricky to negotiate. A lot of what goes on in education is almost certainly not scalable.
While all these help supplementally with direct interactions, most of the format still is non-synchronous. I record lectures (short ones, 4-6 per week constituting a unit), they watch and listen. More interactivity would be beneficial all around.
The chatter around the need to improve education in the U.S. has been going on for decades, but it looks like something is finally going to happen. Why? Because the business model of higher education is truly under attack.
There are good reasons to be skeptical of machines grading essays. Their algorithms can't distinguish between arguments supported by factual evidence and cases built on canards. They're reliable enough to dock points for clichés, but they're not subtle enough to reward subtlety.