Readability

Readability is the ease with which a reader can understand a written text. In natural language, the readability of text depends on its content (the complexity of its vocabulary and syntax) and its presentation (such as typographic aspects like font size, line height, and line length). Researchers have used various factors to measure readability, such as

Speed of perception

Perceptibility at a distance

Perceptibility in peripheral vision

Visibility

Reflex blink technique

Rate of work (reading speed)

Eye movements

Fatigue in reading

Readability is more than simply legibility—which is a measure of how easily a reader can distinguish individual letters or characters from each other.

Higher readability eases reading effort and speed for any reader, but it is especially important for those who do not have high reading comprehension. In readers with average or poor reading comprehension, raising the readability level of a text from mediocre to good can make the difference between success and failure of its communication goals.

Readability exists in both natural language and programming languages though in different forms. In programming, things such as programmer comments, choice of loop structure, and choice of names can determine the ease with which humans can read computer program code.

People have defined readability in various ways, e.g., in: The Literacy Dictionary,Jeanne Chall and Edgar Dale,G. Harry McLaughlin,William DuBay.

Easy reading helps learning and enjoyment, so what we write should be easy to understand.

While many writers and speakers since ancient times have used plain language[citation needed], the 20th century brought more focus to reading ease. Much research has focused on matching prose to reading skills. This has used many successful formulas: in research, government, teaching, publishing, the military, medicine, and business. Many people in many languages have been helped by this.

By the year 2000, there were over 1,000 studies on readability formulas in professional journals about their validity and merit.[9] The study of reading is not just in teaching. Research has shown that much money is wasted by companies in making texts hard for the average reader to read.

There are summaries of this research; see the links in this section. Many textbooks on reading include pointers to readability.

In the 1880s, English professor L. A. Sherman found that the English sentence was getting shorter. In Elizabethan times, the average sentence was 50 words long. In his own time, it was 23 words long.

Sherman's work established that:

Literature is a subject for statistical analysis.

Shorter sentences and concrete terms help people to make sense of what is written.

Speech is easier to understand than text.

Over time, text becomes easier if it is more like speech.

Sherman wrote: "Literary English, in short, will follow the forms of standard spoken English from which it comes. No man should talk worse than he writes, no man should write better than he should talk.... The oral sentence is clearest because it is the product of millions of daily efforts to be clear and strong. It represents the work of the race for thousands of years in perfecting an effective instrument of communication."

In 1889 in Russia, the writer Nikolai A. Rubakin published a study of over 10,000 texts written by everyday people.From these texts, he took 1,500 words he thought most people understood. He found that the main blocks to comprehension are unfamiliar words and long sentences.Starting with his own journal at the age of 13, Rubakin published many articles and books on science and many subjects for the great numbers of new readers throughout Russia. In Rubakin's view, the people were not fools. They were simply poor and in need of cheap books, written at a level they could grasp.

In 1921, Harry D. Kitson published The Mind of the Buyer, one of the first books to apply psychology to marketing. Kitson's work showed that each type of reader bought and read their own type of text. On reading two newspapers and two magazines, he found that short sentence length and short word length were the best contributors to reading ease.

The earliest reading ease assessment is the subjective judgment termed text leveling. Formulas do not fully address the various content, purpose, design, visual input, and organization of a text.Text leveling is commonly used to rank the reading ease of texts in areas where reading difficulties are easy to identify, such as books for young children. At higher levels, ranking reading ease becomes more difficult, as individual difficulties become harder to identify. This has led to better ways to assess reading ease.

In the 1920s, the scientific movement in education looked for tests to measure students' achievement to aid in curriculum development. Teachers and educators had long known that, to improve reading skill, readers—especially beginning readers—need reading material that closely matches their ability. University-based psychologists did much of the early research, which was later taken up by textbook publishers.

Educational psychologist Edward Thorndike of Columbia University noted that, in Russia and Germany, teachers used word frequency counts to match books to students. Word skill was the best sign of intellectual development, and the strongest predictor of reading ease. In 1921, Thorndike published Teachers Word Book, which contained the frequencies of 10,000 words.It made it easier for teachers to choose books that matched class reading skills. It also provided a basis for future research on reading ease.

Until computers came along, word frequency lists were the best aids for grading reading ease of texts.In 1981 the World Book Encyclopedia listed the grade levels of 44,000 words.

In 1943, Rudolf Flesch published his PhD dissertation, Marks of a Readable Style, which included a readability formula to predict the difficulty of adult reading material. Investigators in many fields began using it to improve communications. One of the variables it used was personal references, such as names and personal pronouns. Another variable was affixes.[41]

In 1948, Flesch published his Reading Ease formula in two parts. Rather than using grade levels, it used a scale from 0 to 100, with 0 equivalent to the 12th grade and 100 equivalent to the 4th grade. It dropped the use of affixes. The second part of the formula predicts human interest by using personal references and the number of personal sentences. The new formula correlated 0.70 with the McCall-Crabbs reading tests.[42] The original formula is:

Reading Ease score = 206.835 − (1.015 × ASL) − (84.6 × ASW)

Where: ASL = average sentence length (number of words divided by number of sentences)

ASW = average word length in syllables (number of syllables divided by number of words)

Publishers discovered that the Flesch formulas could increase readership up to 60 percent. Flesch's work also made an enormous impact on journalism. The Flesch Reading Ease formula became one of the most widely-used, tested, and reliable readability metrics. In 1951, Farr, Jenkins, and Patterson simplified the formula further by changing the syllable count. The modified formula is:

New reading ease score = 1.599nosw − 1.015sl − 31.517

Where: nosw = number of one-syllable words per 100 words and

sl = average sentence length in words.

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 grade-level formula.The Flesch–Kincaid formula is one of the most popular and heavily tested formulas. It correlates 0.91 with comprehension as measured by reading tests.

Edit

John Bormuth of the University of Chicago looked at reading ease using the new 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 percent of the questions of a multiple-choice test. The best level for unassisted reading is one for which readers can correctly answer 80 percent of the questions. These cutoff scores were later confirmed by Vygotsky and Chall and Conard.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.

The Lexile framework Edit

In 1988, Jack Stenner and his associates at MetaMetrics, Inc. published a new system, 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.

The Lexile Book Database has more than 100,000 titles from more than 450 publishers. By knowing a student's Lexile score, a teacher can find books that match his or her reading level.[88]

ATOS readability formula for books Edit

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.

CohMetrix psycholinguistics measurements Edit

Coh-Metrix can be used in many different ways to investigate the cohesion of the explicit text and the coherence of the mental representation of the text. "Our definition of cohesion consists of characteristics of the explicit text that play some role in helping the reader mentally connect ideas in the text."[91] The definition of coherence is the subject of much debate. Theoretically, the coherence of a text is defined by the interaction between linguistic representations and knowledge representations. While coherence can be defined as characteristics of the text (i.e., aspects of cohesion) that are likely to contribute to the coherence of the mental representation, Coh-Metrix measurements provide indices of these cohesion characteristics.