Readability estimates are usually based on measures of word difficulty and measures of sentence difficulty. Word difficulty is measured in two ways: by the structural size and complexity of words or by reference to phonomena of language use, such as word-list frequency or the regularity of spelling patterns. Sentence difficulty is measured only in…

This review of findings in the field of readability research discusses the differences in meaning between readability and legibility, examines the origins and developments of readability formulas for children's and adult materials, and describes several of the best-known formulas for English-language materials. (46 references) (Author/LRW)

Raises doubts about the validity of readability formulas. (RB)

Describes a revised readability formula for Vietnamese that differentiates between Vietnamese and Sino-Vietnamese compound words and discusses its validity and reliability. (HOD)

A study examined whether (1) there are untested indices of difficulty that can be used to enhance the accuracy of readability formulas, (2) the same readability formula can be used to assess the readability of text for mature and immature readers and for good and poor readers, and (3) some one model of the reading process or some synthesis of…