[a_geeky_bro]

Did you even read OP's comment? They specifically mentioned the need to engage with students' work to survey their (mis)understandings.

The link you posted to Khan does not automate that delicate balance between teacher and student. It's a bunch of videos of Khan describing the Chain Rule. The "practice" sections are mundane - multiple choice questions or fill in the blanks. You simply cannot (as an educator) see the (mis)understandings of students like this. You need to pour over their work. Take note of where patterns occur and address them next class. Iterative. Do you honestly think Khan has "automated" that?

This thread is full of asinine comments like yours that demonstrate just how much people in tech _don't_ understand what it's like to teach. Hence the original link to 100 fuck ups by engineers, product people, and VCs.