Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Humor
With its crazy cast of characters, absurd situations, and total lack of anything like a real plot, this book seems to have one big goal: to make you laugh. And if Louis Sachar can't make you laugh with one story, he has twenty-nine more to keep trying.
Each story has a humorous twist and ends with a punchline—who can forget Calvin saying, "but really, it was nothing" (7.54), after he tries to find the invisible nineteenth floor? How about Mrs. Jewls freaking out about her class full of monkeys? "I'm a teacher, not a zookeeper!" (2.8) she exclaims. Sachar's specialty is finding ways to turn regular school-day situations on their heads to make fun of everyday life in a classroom.
And speaking of turning things on their heads, Sachar even does funny things with the book itself—when John stands on his head in Chapter 17, the words on the page are printed upside down. It's hard to take a book seriously when you're standing on your head to read it. Unless you just flip the book over, but that's not nearly as fun, is it?