Also, if I may add another question to the mix, how much does the actor’s own innate ability play a role? Perhaps my comparison is wrong, but I think of acting coaches–regardless of method–the same way I think of athletic coaches and instructors: a good one might be able to polish a raw talent but the talent has to be there to begin with. Any coach or instructor can guide me on how to deliver Marc Antony’s funeral speach for Caesar, make jump shots, or throw a baseball, but that won’t turn me into Marlon Brando, Michael Jordan, or Pedro Martinez.