Neil Gaiman set a difficult task for himself when he was writing The Graveyard Book. He talks about it in his acceptance speech for the 2009 Newbery Medal:
I wanted the book to be composed of short stories because The Jungle Book was composed of short stories. I wanted it to be a novel because it was a novel in my head. The tension between those two things was both a delight and a heartache as a writer. (source)
A book of short stories (even if it is all about a single main hero and has a bunch of other characters) usually has some connecting thread or central themes that hold the stories together as a book. But, each story can stand alone, independent of the other stories. You can read just one story from the collection and not lose much meaning if you don’t read the other ones.
With a novel, though, you probably want to read the whole thing, from front to back. The hero takes a journey that we can only understand when he or she gets to the end of it.
What Neil Gaiman wanted to do was combining the short story style with a novel.
It’s easy to see how The Graveyard Book is like a short story collection. Each chapter (except for the Interlude) is a different episode in Bod’s life, as he grows from toddler to teen under the guidance of a bunch of supernatural characters. For example, Gaiman wrote and published Chapter 4, “The Witch’s Headstone,” before the other Graveyard Book stories and it works OK as a stand-alone story.
But, if "The Witches Headstone" isn't part of a larger story (or novel), then we're left with a confusing piece. That piece is the “black edged” card that says “Jack” on it. Even if we haven’t read any of the other chapters, we can figure out the basics. We understand that Bod’s a live boy who is, for some reason, living in a graveyard and being raised by dead people. But you can’t drop something big like a black-edged card into a story, make a big deal about it, and then never explain why it’s so darn important. Well, you can, but it might bother some readers, and then you'll get bad reviews on Amazon.com.
Chapter 4 still mostly gives us that satisfied feeling of reading a complete story. This is because Bod starts this adventure with a goal (to get a headstone for Liza) and he finishes that mission by the end of the chapter.
But, to really appreciate Chapter 4, readers need to know Bod better, to understand that he’s not just a kindhearted boy who randomly lives in a graveyard. He's actually a hero whose birth was predicted thousands of years ago, and who’s been destined to be the one to rid the world of a horrible evil (the Jacks). Unless we know all this, it won’t be so important that our hero is able to see through illogical prejudices (about people buried in Potters Fields, like Liza). Or that he's willing to risk his own safety to make life better for someone he just met because he can tell she’s gotten a raw deal – in life and in death. This is just one example of why we think The Graveyard Book succeeds in blending together two forms and creating something new: a shnovel.
Now, if you’ve only read The Graveyard Book once, we totally recommend a second read. When you read it again, you can really see all the little details that connect the book, even though it might seem to be just a bunch of different stories. For example, recall that the ghouls in Chapter 3 say, “Skagh! Thegh! Kavagh!” (3.123) to open the ghoul gate. When Bod uses these same magic words to open the ghoul gate in Chapter 7, we then understand that he kept the information in his memory for years, and remembers on it to fight the Jacks. What other details like this can you find?