Readability formulas were originally conceived of as being evaluative measures. However, if a text is being rewritten or revised so that it matches a particular level of ability in its intended readers, it is rather inescapable that readability formulas will influence the changes made. Tacitly or not, formulas now are used to diagnose what causes…

Readability formulas have varied uses. In education they are used to match children's reading ability to the difficulty level of material, select stories and books for classroom use and for individual students' particular needs, select textbooks and other reading materials, aid educational research, and check reading materials of newly literate…