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In addition to Steven Spielberg, other candidates for the director's chair were Jonathan Demme, Terry Gilliam, Mike Newell, Alan Parker, Wolfgang Petersen, Rob Reiner, Ivan Reitman, Tim Robbins, Brad Silberling, M. Night Shyamalan, and Peter Weir. Newell directed the fourth entry of the series, Harry Potter and the Goblet of Fire (2005). Gilliam was J.K. Rowling's first choice, but the studio finally picked Chris Columbus to direct, because he had experience directing child actors and actresses. Columbus was also asked many times by his daughter to direct, and he agreed after he read her copy of the book.
Alan Rickman was handpicked to play Snape by J.K. Rowling, and received special instructions from her about the character. Rowling even provided him with vital details of Snape's backstory, not revealed until the final novel.
The child actors and actresses would do their actual schoolwork in the movie, to make the school setting more real.
Richard Harris, who had been acting for more than forty years by the time this movie entered production, stated that he had never been involved with a cast that was as close as this one.
Richard Harris had trouble remembering his lines, and Daniel Radcliffe would ask him to help with running his lines, just to give Harris more practice.
The Hogwarts' motto, "Draco dormiens nunquam titillandus", means "never tickle a sleeping dragon".