As others have previously said, you really need to read the book in order to understand all the "inside" information about the characters and why they react the way they do. I think the movie did a very good job portraying the characters, except for Jasper. It was not revealed in the movie the reason as to why he always wears that pained expression (his ability to calm those around him who are upset). I think Alice's part should have matched her importance from the book. Also, it is helpful to know that Victoria and James were "involved" more deeply than what was led on, which explains her reaction at the very end of the movie. Overall, I think it was a good adaptation of the book, very entertaining, and I look forward to the sequels.