Very clearly written by teachers, by which I mean it reads like a textbook — unfortunately, imo this is completely at odds with its subject. Excruciatingly detailed attempts to define the minutiae, which is fine for an indepth-reference but not so much the beginner's guide I thought it was meant to be. Some interesting exercises and examples (though haikus aren't just for kids! Also I was quite bemused by some of the chapter groupings), but definitely not a go-to source.