It's important for a director to provide as much information, especially when we're working with things that we have to conceive out of thin air. You can't just expect an actor to understand: 'Oh, there's a dinosaur coming at you". OK, so I'm going to automatically know how big it is and what it sounds like? I need details. How close does he get to me? How tall is he? What will the impact be of his cry when he's screaming at me or when he's blowing smoke or air in my face?