When I'm writing handouts that I want to give clients I will sometimes run
them threw my word processing grammer checker and check readability level.
 Sometimes you may need to buy software for this. Grammatik was one
standalone style checker that contained readability indexes. You might also
look for shareware on line to perform the same functions. The secret to
readability is short, short words, short sentences, shorter paragraphs, keep
everything brief.
 ( my english teacher/computer expert husband butted in here)

Linda
Clarkston, Wa.