I am a children's librarian, with many years' experience with preschool storytimes. This is a classic concept book, and one of my favorites. As a read-aloud, I like it better than Eric Carle's more recent Little Cloud. The repetition not only engages the children, it makes it easy for them to respond successfully. "It looked like ..." gives them a chance to identify the shape, with no wrong answers, because the next phrase is "But it wasn't a wasn't a ..." for all. By the time the last page revals that "It was just a cloud in the sky" most of them have guessed,and are pretty proud of themselves. It might be too long for many groups (he wrote it for a pre-television audience) but it is easy to skip pages or speed up. Makes a great feltboard using quilt batting.