I've worked with various online homework systems in mathematics for five years. They have not improved demonstrably in that time. I've taken a couple MOOCs, an

I've worked with various online homework systems in mathematics for five years. They have not improved demonstrably in that time. I've taken a couple MOOCs, and have not been terribly impressed with the mechanical grading algorithms. Teachers may be replaced by software, but I don't believe the substitution is of equal for equal.