Editing Readability (section)

=== Readability studies ===

During the recession of the 1930s, the U.S. government invested in [[adult education]]. In 1931, [[Douglas Waples]] and [[Ralph W. Tyler|Ralph Tyler]] published ''What Adults Want to Read About.'' It was a two-year study of adult reading interests. Their book showed not only what people read but what they would like to read. They found that many readers lacked suitable reading materials: they would have liked to learn but the reading materials were too hard for them.<ref name="Waples">Waples, D. and R. Tyler. 1931. ''What adults want to read about.''Chicago: University of Chicago Press.</ref>

[[Lyman Bryson]] of [[Teachers College, Columbia University]] found that many adults had poor reading ability due to poor education. Even though [[college]]s  had long tried to teach how to write in a clear and readable style, Bryson found that it was rare. He wrote that such language is the result of a "...[[discipline]] and artistry that few people who have ideas will take the trouble to achieve... If simple language were easy, many of our problems would have been solved long ago."<ref name="KlareBuck3" /> Bryson helped set up the Readability Laboratory at the college. Two of his students were Irving Lorge and [[Rudolf Flesch]].

In 1934, Ralph Ojemann investigated adult reading skills, factors that most directly affect reading ease, and causes of each level of difficulty. He did not invent a formula, but a method for assessing the difficulty of materials for [[parent education]]. He was the first to assess the validity of this method by using 16 magazine passages tested on actual readers. He evaluated 14 measurable and three reported factors that affect reading ease.

Ojemann emphasized the reported features, such as whether the text was coherent or unduly abstract. He used his 16 passages to compare and judge the reading ease of other texts, a method now called ''scaling''. He showed that even though these factors cannot be measured, they cannot be ignored.<ref name="Ojemann">Ojemann, R. H. 1934. "The reading ability of parents and factors associated with reading difficulty of parent-education materials." ''University of Iowa studies in child welfare'' 8:11–32.</ref>

Also in 1934, [[Ralph W. Tyler|Ralph Tyler]] and [[Edgar Dale]] published the first adult reading ease formula based on passages on health topics from a variety of textbooks and magazines. Of 29 factors that are significant for young readers, they found ten that are significant for adults. They used three of these in their formula.<ref name="DaleTyler">Dale, E. and R. Tyler. 1934. "A study of the factors influencing the difficulty of reading materials for adults of limited reading ability." ''Library quarterly'' 4:384–412.</ref>

In 1935, [[William S. Gray]] of the [[University of Chicago]] and Bernice Leary of [[Saint Xavier University|Xavier College in Chicago]] published ''What Makes a Book Readable,'' one of the most important books in readability research. Like Dale and Tyler, they focused on what makes books readable for adults of limited reading ability. Their book included the first scientific study of the reading skills of American adults. The sample included 1,690 adults from a variety of settings and regions. The test used a number of passages from [[newspaper]]s, magazines, and books—as well as a standard reading test. They found a mean grade score of 7.81 (eighth month of the [[seventh grade]]). About one-third read at the 2nd to 6th-[[grade level]], one-third at the 7th to 12th-grade level, and one-third at the 13th–17th grade level. The authors emphasized that one-half of the adult population at that time lacked suitable reading materials. They wrote, "For them, the enriching values of reading are denied unless materials reflecting adult interests are adapted to their needs." The poorest readers, one-sixth of the adult population, need "simpler materials for use in promoting functioning [[literacy]] and in establishing fundamental reading habits."<ref name="Gray">Gray, W. S. and B. Leary. 1935. ''What makes a book readable''. Chicago: Chicago University Press.</ref>

In 1939, Irving Lorge published an article that reported other combinations of variables that indicate difficulty more accurately than the ones Gray and Leary used. His research also showed that, "The vocabulary load is the most important concomitant of difficulty."<ref name="Lorge1939">Lorge, I. 1939. "Predicting reading difficulty of selections for children. ''Elementary English Review'' 16:229–233.</ref> In 1944, Lorge published his ''Lorge Index'', a readability formula that used three variables and set the stage for simpler and more reliable formulas that followed.<ref name="Lorge1944b">Lorge, I. 1944. "Predicting readability." ''Teachers college record'' 45:404–419.</ref>

By 1940, investigators had:
* Successfully used statistical methods to analyze reading ease
* Found that unusual words and sentence length were among the first causes of reading difficulty
* Used vocabulary and sentence length in formulas to predict reading ease