The instrument looks at word length ( number of letters ) and sentence length ( number of words ) and produces a score sd of Ohio State , Jeanne S. Chall of the Reading Laboratory of Harvard , and George R. Klare of Ohio University .
The instrument looks at word length ( number of letters ) and sentence length ( number of words ) and produces a score that is tied to a U.S. grade school level . 
 Others who later led plain language and readability research include educator Edgar Dale of Ohio State , Jeanne S. Chall of the Reading Laboratory of Harvard , and George R. Klare of Ohio University .