How does the film version of A Separate Peace by John Knowles compare to the book?

John Knowles's book A Separate Peace is similar to the movie adaptation of the story, but there are several important differences. Overall, the message is the same and the events unfold the same way in both versions. The main differences exist in the way the story is set up and the way the literary elements develop throughout. Here are some examples:
In the book you get a clear idea of who is telling the story. Gene functions as your interpreter of the story--he offers a narrative that connects a reader with the book. The use of a narrator in the book helps to draw in a reader and generates sympathy, which makes the story more meaningful. In the movie, the director chose not to use this technique. Instead of using a narrator, the director chose to create a wall between the viewer and the story, which served a different purpose. Rather than pull a reader in to experience the story directly, the director chose to create some distance, which allowed the viewers to keep an open mind about all of the characters and events. Instead of being biased to one character, as in the book, the viewers could choose whose viewpoint to sympathize with.
In the book, the narrative offers a reader insight as to the emotions and inner conflicts of the characters, especially Gene. Unfortunately, the movie doesn't offer the same insight, so the viewer is left to interpret what the characters may or may not be thinking and feeling. Since we've already established that the lack of narrative contributed to some distance, it's worth noting that this added even more distance for movie watchers.
The book didn't spend a whole lot of time on external elements, such as timing, place, and setting. The majority of the book's time was spent on internal dialogue and plot. In the movie, you get more information about the way the scenes looked because movies are inherently more visual. Whereas in the book you might feel as if you accompany the character directly, the movie makes you feel as if you're viewing a setting through a window--the effect certainly resonates differently with an audience.