a quote . . .

What strikes me as essential are that a haiku be: (1) brief (as long as it needs to be, as short as it can be); (2) a concatenation of words (this is, after all, a literary art, and the words of a haiku are not the experience it contains; on the other hand, the words of the haiku are another and new experience); (3) an opening (to something, though not always the same thing, but always larger than the flat description would be by itself). – Jim Kacian