I’ve seen very graphically how to lose an audience, how to gain an audience, and how to keep an audience,” he laughs. “We did some tests and that was a hell of a thing. It was like opening out of town. I could feel the energy in a room dissipate during a scene, or I could feel people get excited. Or I could see people walk out. Ah! Any of those things will tell you something. You may get 15 different reasons [from test audiences] why a scene doesn’t work, and none of those reasons will be right, but if every single person is telling you for some stupid-sounding reason that a scene doesn’t work, probably the scene doesn’t work. None of them can put their finger on why.”
[...]
“It has always been my ambition to never have a director’s cut, that the best movie I can put out is the one I’m putting out,” says the filmmaker. “Even though I took things out, I did it for a reason. There’s an old saying amongst writers and directors: Kill your children. If it’s not working, pull them.”
-- Joss Whedon on Serenity over at Playing Now



