While readability formulas are intended to help writers and teachers of
business communications, the formulas have in fact been counter-productive
in several ways. The formulas don't really help writers to predict the reada
bility of their prose because they oversimplify, because they have not been
calibrated for adult readers, and because reading is so highly individual. In
addition, the formulas don't help writers to produce readable documents
either; though short sentences and words correlate with difficulty, they do
not cause difficulty. Finally, the formulas hamper the teaching of business
writing because they emphasize written products instead of the process of
writing and because they discourage teachers from employing practical
techniques that can develop students' abilities to manipulate stylistic
options.