. >> there was a midterm exam that was the same, a final exam that was the same attanfd. there were home work assignments. they were graded so we made choice questions. but at the end of the day we could say, like, if a student performed at this level would we give the student a passing grade at stanford and the answer was yes. for 23,000 students which means in this quarter my colleague and i taught more students in the world artificial intelligence than all professors together. >> rose: you have said you can probably get the same quality of education you in each class with 1% to 2% of the cost. sohen i taught this class i taught it online and of my 200 stanford students, about 170 chose to view me online. >> rose: and didn't come to the classroom. >> and i was surprised so i asked them what's going on? you paid a lot of money to see me in person, the famous professor and you're not even bothering coming to class? >> and they would say "we prefer you on video." and i would say why? and they would say, professor, for one we can remind you so you can check the same thing a