In the traditional education system, what is fixed is how long you have to learn something, and then what is variable is how well you've learned it. You've got an A, a B, a C, and then, despite the fact that you have that 10%, 20%, 30% gap, you then build on that foundation... So what we're saying is, what we hold fixed now isn't the amount of time to learn the subject, it's the expectation of mastery. That's what's fixed, and the variable here... is actually how long you have to spend on that topic.

What we think happens is, you know, people talk about 'student to teacher' ratio, but the really important metric is 'student to valuable interactive time with the teacher and his or her peers' ratio. And that ratio, based on what we've seen in Los Altos so far, has frankly just gone through the roof.