I already mentioned Amazon’s text stats in a post where I tried to explain why they were far from being useful in every situation: A note on Amazon’s text readability stats, published last December.
I found an example which shows particularly well why you cannot rely on these statistics when it comes to get a precise picture of a text’s readability. Here are the screenshots of text statistics describing two different books (click on them to display a larger view):
The two books look quite similar, except for the length of the second one, which seems to contain significantly more words and sentences.
The first book (on the left) is Pippi Longstocking, by Astrid Lindgren, whereas the second is The Sound and The Fury, by William Faulkner… The writing style could not be more different, however, the text statistics make them appear quite close to each other.
The criteria used by Amazon are too simplistic, even if they usually perform acceptably on all kind of texts. The readability formulas that output the first series of results only take the length of words and sentences into account and their scale is designed for the US school system. In …more ...