I had to teach online during a weather emergency decades ago(back when you used powerpoint and a RealPlayer product to make movies). No live lectures though- a

I had to teach online during a weather emergency decades ago(back when you used powerpoint and a RealPlayer product to make movies). No live lectures though- all we had was dial-up so it was all asynchronous. One thing that it seems to me would be very helpful would be an instantaneous feedback channel where you could have premade questions (say, multiple-choice) and ask students to answer them in real time. This would allow you intersperse formative assessment into your lectures more like what happens live. It would go a long way toward helping the class be interactive. They would have to be graded automatically for large classes, of course.