Improv is not something I had a lot of experience with, because for a long time, my only experience in front of a camera was all television, which is pretty rigid script-wise, except for the occasional scene where you toss in an ad-lib just to elongate something. Like, say, you're walking down a hall and you just don't have enough dialogue, and you throw in something. But you don't really have time to do other than what's written. It's very rigid. Shows have a certain rhythm that nobody wants disturbed.