Jim Rash

When you're talking about people like Shonda Rhimes, Vince Gilligan or Beau Willimon, you're talking to people who are notable and celebrities in their own right. People want to know how their brains work.

Frankly, as much as I love to improvise, it hasn't been difficult to stick to the script on 'Mad Men.' The writing is so precise, and the story so carefully crafted, that I don't think there's room - or need - for ad libbing. I could never come up with dialogue as lovely as these writers do, anyway.