Check out Wendell Dryden's thoughtful post "Readability - Form and Substance" on his blog: qualities - communities - literacies. Wendell raises an interesting point about how the readability of a story is aided or complicated by decisions regarding the way words and letters are displayed on a page. He uses newspapers, Green Eggs and Ham and My Car as examples to compare and contrast word alignment in the text and various writing conventions. He goes on to discuss how editorial choices influence the success of both youth and adult readers.
As a writer of children's books -- picture books in particular -- I'm always very conscious of word choice. How does each word best convey my story? Does the reading level meet the needs of my target audience? I read everything out loud, more than once, to check sentence fluency - the way words and phrases flow together.
As a library media specialist, I'm concerned with finding books with an appropriate reading level for each student on a daily basis. Wendell shines a light on another component to consider.