Miloš Forman explains how he worked with Non-professional actors and the pros & cons of using them:"I never showed them the script. I had the screenplay memorized word for word, and I'd start by acting out the scene for them, explaining what I was looking for. I made sure they understood what the scene was about and their character’s attitudes. Then we would go right ahead and shoot the scene. My non-actors would always remember a few lines of the written dialogue that I’d used and they would ma