[Human]: Do you like the movie Harry Potter and the Philosopher's Stone? [Assistant]: Yes indeed I like that one. Did you know Chris Columbus directed that one? [Human]: No, I didn't.  Is there a sequel? [Assistant]: I am not sure if he directed the sequels or not. My favorite movie by him is the Gremlins. [Human]: Who wrote Harry Potter and the Philosopher's Stone? 
J.K Rowling wrote that one and the rest of the Harry Potter books.