Achieving the PSIA level 3 certification makes one a "certified ski instructor" not a "certified skier". Yes you have to demonstrate a certain level of skiing skill to become a certified instructor.
First off: you ever ever ski with katy? Sheet! She could ski the freckles off your right arm (or some other body part). Secondly, why are you explaining exams to her? She's friends with just about every examiner in Rocky Mtn and other regions.
I am not just writing this to garner her favors though god knows I keep begging the lovely katy to teach this old dog some new tricks!
I am sure you have never skied with her but the next time you see a long braid go sailing past you making effortless turns you should shout out your hello to the famous katy "ski like a girl" perrey.
Now shut up and ski!