Editing Readability (section)

=== Formula refinement and variants ===

In the 1940s, Robert Gunning helped bring readability research into the workplace. In 1944, he founded the first readability consulting firm dedicated to reducing the "fog" in newspapers and business writing. In 1952, he published ''The Technique of Clear Writing'' with his own Fog Index, a formula that correlates 0.91 with comprehension as measured by reading tests.<ref name="DuBay" />

[[Edgar Dale]], a professor of education at Ohio State University, was one of the first critics of Thorndike's vocabulary-frequency lists. He claimed that they did not distinguish between the different meanings that many words have. He created two new lists of his own. One, his "short list" of 769 easy words, was used by Irving Lorge in his formula. The other was his "long list" of 3,000 easy words, which were understood by 80% of fourth-grade students. However, one has to extend the word lists by regular plurals of nouns, regular forms of the past tense of verbs, progressive forms of verbs etc. In 1948, he incorporated this list into a formula he developed with [[Jeanne Chall|Jeanne S. Chall]], who later founded the Harvard Reading Laboratory. In 1995, Dale and Chall published a new version of their formula with an upgraded word list, the New Dale–Chall readability formula.<ref name="Dale-Chall2">Chall, J. S. and E. Dale. 1995. ''Readability revisited: The new Dale–Chall readability formula.'' Cambridge, MA: Brookline Books.</ref>

The [[Spache readability formula]] was developed in 1952.

In 1963, while teaching English teachers in Uganda, Edward Fry developed his [[Fry readability formula|Readability Graph]]. It became one of the most popular formulas and easiest to apply.<ref name="Fry">Fry, E. B. 1963. ''Teaching faster reading''. London: Cambridge University Press.</ref><ref name="Fry2">Fry, E. B. 1968. "A readability formula that saves time." '' Journal of reading '' 11:513–516.</ref>

The [[automated readability index]] was developed in 1967.

Harry McLaughlin  determined that word length and sentence length should be multiplied rather than added as in other formulas. In 1969, he published his SMOG (Simple Measure of Gobbledygook) formula. It is often recommended for use in healthcare.<ref name="Doak">Doak, C. C., L. G. Doak, and J. H. Root. 1996. ''Teaching patients with low literacy skills''. Philadelphia: J. B. Lippincott & Co.</ref>

The Golub Syntactic Density Score was developed by Lester Golub in 1974.{{cn|date=September 2024}}

In 1973, a study commissioned by the US military of the reading skills required for different military jobs produced the FORCAST formula. Unlike most other formulas, it uses only a vocabulary element, making it useful for texts without complete sentences. The formula satisfied requirements that it would be:
* Based on Army-job reading materials.
* Suitable for the young adult-male recruits.
* Easy enough for Army clerical personnel to use without special training or equipment.<ref name="forcast" />

In 1975, in a project sponsored by the U.S. Navy, the Reading Ease formula was recalculated to give a grade-level score. The new formula is now called the [[Flesch–Kincaid readability tests|Flesch–Kincaid grade-level]] formula.<ref name="Kincaid">Kincaid, J. P., R. P. Fishburne, R. L. Rogers, and B. S. Chissom. 1975. ''Derivation of new readability formulas (Automated Readability Index, Fog Count, and Flesch Reading Ease Formula) for Navy enlisted personnel.'' CNTECHTRA Research Branch Report 8-75.</ref>

The [[Linsear Write]] Raygor readability estimate was developed in 1977.

In 1978, John Bormuth of the University of Chicago looked at reading ease using the new [[Cloze test|Cloze deletion test]] developed by Wilson Taylor. His work supported earlier research including the degree of reading ease for each kind of reading. The best level for classroom "assisted reading" is a slightly difficult text that causes a "set to learn", and for which readers can correctly answer 50% of the questions of a multiple-choice test. The best level for unassisted reading is one for which readers can correctly answer 80% of the questions. These cutoff scores were later confirmed by Vygotsky<ref name="Vygotsky">Vygotsky, L. 1978. ''Mind in society.'' Cambridge, MA: Harvard University Press.</ref> and Chall and Conard.<ref name="ChallConard">Chall, J. S. and S. S. Conard. 1991. ''Should textbooks challenge students? The case for easier or harder textbooks.'' New York: Teachers College Press.</ref>
Among other things, Bormuth confirmed that vocabulary and sentence length are the best indicators of reading ease. He showed that the measures of reading ease worked as well for adults as for children. The same things that children find hard are the same for adults of the same reading levels. He also developed several new measures of cutoff scores. One of the most well known was the ''Mean Cloze Formula'', which was used in 1981 to produce the ''Degree of Reading Power'' system used by the College Entrance Examination Board.<ref name="Bormuth">Bormuth, J. R. 1966. "Readability: A new approach." ''Reading research quarterly 1:79–132.''</ref><ref name="Bormuth2">Bormuth, J. R. 1969. ''Development of readability analysis'': Final Report, Project no 7-0052, Contract No. OEC-3-7-0070052-0326. Washington, D. C.: U. S. Office of Education, Bureau of Research, U. S. Department of Health, Education, and Welfare.</ref><ref name="Bormuth3">Bormuth, J. R. 1971. ''Development of standards of readability: Towards a rational criterion of passage performance.'' Washington, D. C.: U. S. Office of Education, Bureau of Research, U. S. Department of Health, Education, and Welfare.</ref>

In 1988, Jack Stenner and his associates at MetaMetrics, Inc. published the [[Lexile]] Framework for assessing readability and matching students with appropriate texts. The Lexile framework uses average sentence length, and average word frequency in the American Heritage Intermediate Corpus to predict a score on a 0–2000 scale. The AHI Corpus includes five million words from 1,045 published works often read by students in grades three to nine.{{Citation needed|date=February 2024}}<!--what's this trying to say?-->

In 2000, researchers of the School Renaissance Institute and Touchstone Applied Science Associates published their Advantage-TASA Open Standard (ATOS) Reading ease Formula for Books. They worked on a formula that was easy to use and that could be used with any  texts.

The project was one of the widest reading ease projects ever. The developers of the formula used 650 normed reading texts, 474 million words from all the text in 28,000 books read by students. The project also used the reading records of more than 30,000 who read and were tested on 950,000 books.

They found that three variables give the most reliable measure of text reading ease:

*words per sentence
*average grade level of words
*characters per word

They also found that:

*To help learning, the teacher should match book reading ease with reading skill.
*Reading often helps with reading gains.
*For reading alone below the 4th grade, the best learning gain requires at least 85% comprehension.
*Advanced readers need 92% comprehension for independent reading.
*Book length can be a good measure of reading ease.
*Feedback and interaction with the teacher are the most important factors in reading.<ref name="atos">School Renaissance Institute. 2000. ''The ATOS readability formula for books and how it compares to other formulas.'' Madison, WI: School Renaissance Institute, Inc.</ref><ref name="Paul">Paul, T. 2003. ''Guided independent reading.'' Madison, WI: School Renaissance Institute, Inc. [http://www.renlearn.com/GIRP2008.pdf  http://www.renlearn.com/GIRP2008.pdf]</ref>