Everything You Always Wanted To Know about Readability but Were Afraid To Ask.
Allen M. Blair · 1971
For one thing, word lists and formulas aren't absolutesand they don't pretend to be. They are probability statements. Let's say you use a readibility formula to estimate the reading level of a book. And you come up with a score of grade 5. Just what does that score mean? Certainly not that all fifth graders can easily read that book. Or even that all people reading at fifth-grade level can easily read it. No, the score says chances are that many fifthgrade-level readers will have little trouble with the bookperhaps 5 to 7 out of 10 such readers. That's all the score means. And that's all it can mean. Because there are too many things the formulas don't measure. Most formulas concentrate on measuring sentence length and vocabulary. Some try to measure also grammatical relationships. And commonness or uncommonness of sen-