Word length and phrase length influence the ease of reading and understanding of a given text. Short words are usually more common (Zipf's law). Short sentences require less abstraction ability to understand. The readability analysis could be useful to make a text better, augmenting its accessibility.
Why have we developed this?
The readability index tells us how easy a given text is to understand. A well-written text is effective, easy to understand and quick to read. This index helps us understand the text's complexity in order to better schedule the activities of translators and revisers. More than ever, written information, especially in the Internet, must be direct and well structured. This analysis can help achieve both goals.