MS sci course length

Hi Lorraine, You can count the units for yourself, maybe see a unit and gauge how long the course must be. By "length" do you mean how long it'll take a student to master the course?

Study duration is very hard to tell on Khan Academy because it's a mastery learning platform. Here, it's not about how long it takes but how well one masters. That isn't to say that a student will take infinitely long to master, but that study duration is a function of mastery, not the other way around. It's the mastery goal that is fixed, and curiously this can work even in strictly timed settings like school or college semesters—as it has for thousands of classrooms! :)