Flesch-Kincaid Readability Test
Encyclopedia
The Flesch/Flesch–Kincaid readability test
s are designed to indicate comprehension difficulty when reading a passage of contemporary academic English. There are two tests, the Flesch Reading Ease, and the Flesch–Kincaid Grade Level. Although they use the same core measures (word length and sentence length), they have different weighting factors, so the results of the two tests correlate approximately inversely: a text with a comparatively high score on the Reading Ease test should have a lower score on the Grade Level test. Both systems were devised by Rudolf Flesch
.
The F-K formula was first used by the US Army for assessing the difficulty of technical manuals in 1978 and soon after became the Department of Defense military standard. The commonwealth of Pennsylvania was the first state in the US to require that automobile insurance policies be written at no higher than a ninth grade level of reading difficulty, as measure by the F-K formula. This is now a common requirement in many other states and for other legal documents such as insurance policies.
Scores can be interpreted as shown in the table below.
Reader's Digest
magazine has a readability index of about 65, Time magazine scores about 52, an average 6th grade student's (an 11-year-old) written assignment has a readability test of 60–70 (and a reading grade level of 6–7), and the Harvard Law Review
has a general readability score in the low 30s. The highest (easiest) readability score possible is around 120 (e.g. every sentence consisting of only two one-syllable words). The score does not have a theoretical lower bound. It is possible to make the score as low as you want by including words with arbitrarily many syllables. This sentence, for example, taken as a reading passage unto itself, has a readability score of about 18.5. This paragraph has a readability score of 19.1. The sentence, "The Australian platypus is seemingly a hybrid of a mammal and reptilian creature" is a 24.4. This article has a readability score of around 42.0.
Many government agencies require documents or forms to meet specific readability levels.
The U.S. Department of Defense
uses the Reading Ease test as the standard test of readability for its documents and forms. Florida requires that life insurance
policies have a Flesch Reading Ease score of 45 or greater.
Use of this scale is so ubiquitous that it is bundled with popular word processing
programs and services such as KWord
, IBM Lotus Symphony
, Microsoft Office Word, WordPerfect
and WordPro.
Long words affect this score significantly more than they do the grade level score.
These readability tests are used extensively in the field of education
. The "Flesch–Kincaid Grade Level Formula" translates the 0–100 score to a U.S. grade level, making it easier for teachers, parents, librarians, and others to judge the readability level of various books and texts. It can also mean the number of years of education generally required to understand this text, relevant when the formula results in a number greater than 10. The grade level is calculated with the following formula:
The result is a number that corresponds with a grade level. For example, a score of 8.2 would indicate that the text is expected to be understandable by an average student in 8th grade (usually around ages 12–14 in the United States of America). The sentence, "The Australian platypus is seemingly a hybrid of a mammal and reptilian creature" is a 13.1 as it has 26 syllables and 13 words. This page has the score of 12.1.
The lowest grade level score in theory is −3.40, but there are few real passages where every sentence consists of a single one-syllable word. Green Eggs and Ham
by Dr. Seuss
comes close, averaging 5.7 words per sentence and 1.02 syllables per word, with a grade level of −1.3. (Most of the 50 used words are monosyllabic
; "anywhere", which occurs 8 times, is the only exception.)
Readability test
For the main article, see ReadabilityReadability tests, readability formulas, or readability metrics are formulae for evaluating the readability of text, usually by counting syllables, words, and sentences. Readability tests are often used as an alternative to conducting an actual statistical...
s are designed to indicate comprehension difficulty when reading a passage of contemporary academic English. There are two tests, the Flesch Reading Ease, and the Flesch–Kincaid Grade Level. Although they use the same core measures (word length and sentence length), they have different weighting factors, so the results of the two tests correlate approximately inversely: a text with a comparatively high score on the Reading Ease test should have a lower score on the Grade Level test. Both systems were devised by Rudolf Flesch
Rudolf Flesch
Rudolf Flesch was an author , and also a readability expert and writing consultant who was a vigorous proponent of plain English in the United States. He created the Flesch Reading Ease test and was co-creator of the Flesch-Kincaid Readability Test...
.
History
"The Flesch–Kincaid" (F–K) Reading grade level was developed under contract to the United States Navy in 1975 by J. Peter Kincaid and his team. Other related US Navy research directed by Kincaid delved into high tech education (for example, the electronic authoring and delivery of technical information); usefulness of the Flesch–Kincaid readability formula; computer aids for editing tests; illustrated formats to teach procedures; and the Computer Readability Editing System (CRES).The F-K formula was first used by the US Army for assessing the difficulty of technical manuals in 1978 and soon after became the Department of Defense military standard. The commonwealth of Pennsylvania was the first state in the US to require that automobile insurance policies be written at no higher than a ninth grade level of reading difficulty, as measure by the F-K formula. This is now a common requirement in many other states and for other legal documents such as insurance policies.
Flesch Reading Ease
In the Flesch Reading Ease test, higher scores indicate material that is easier to read; lower numbers mark passages that are more difficult to read. The formula for the Flesch Reading Ease Score (FRES) test isScores can be interpreted as shown in the table below.
| Score | Notes |
|---|---|
| 90.0–100.0 | easily understandable by an average 11-year-old student |
| 60.0–70.0 | easily understandable by 13- to 15-year-old students |
| 0.0–30.0 | best understood by university graduates |
Reader's Digest
Reader's Digest
Reader's Digest is a general interest family magazine, published ten times annually. Formerly based in Chappaqua, New York, its headquarters is now in New York City. It was founded in 1922, by DeWitt Wallace and Lila Bell Wallace...
magazine has a readability index of about 65, Time magazine scores about 52, an average 6th grade student's (an 11-year-old) written assignment has a readability test of 60–70 (and a reading grade level of 6–7), and the Harvard Law Review
Harvard Law Review
The Harvard Law Review is a journal of legal scholarship published by an independent student group at Harvard Law School.-Overview:According to the 2008 Journal Citation Reports, the Review is the most cited law review and has the second-highest impact factor in the category "law" after the...
has a general readability score in the low 30s. The highest (easiest) readability score possible is around 120 (e.g. every sentence consisting of only two one-syllable words). The score does not have a theoretical lower bound. It is possible to make the score as low as you want by including words with arbitrarily many syllables. This sentence, for example, taken as a reading passage unto itself, has a readability score of about 18.5. This paragraph has a readability score of 19.1. The sentence, "The Australian platypus is seemingly a hybrid of a mammal and reptilian creature" is a 24.4. This article has a readability score of around 42.0.
Many government agencies require documents or forms to meet specific readability levels.
The U.S. Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...
uses the Reading Ease test as the standard test of readability for its documents and forms. Florida requires that life insurance
Life insurance
Life insurance is a contract between an insurance policy holder and an insurer, where the insurer promises to pay a designated beneficiary a sum of money upon the death of the insured person. Depending on the contract, other events such as terminal illness or critical illness may also trigger...
policies have a Flesch Reading Ease score of 45 or greater.
Use of this scale is so ubiquitous that it is bundled with popular word processing
Word processing
Word processing is the creation of documents using a word processor. It can also refer to advanced shorthand techniques, sometimes used in specialized contexts with a specially modified typewriter.-External links:...
programs and services such as KWord
KWord
Calligra Words is a free word processor, part of Calligra Suite and developed by KDE.The text-layout scheme in Words is based on frames, making it similar to FrameMaker by Adobe. These can be placed anywhere on the page, and can incorporate text, graphics and embedded objects...
, IBM Lotus Symphony
IBM Lotus Symphony
IBM Lotus Symphony is a suite of applications for creating, editing, and sharing text, spreadsheet, presentations and other documents, and is currently distributed as freeware. First released in 2007, the suite has a name similar to the 1980s DOS suite Lotus Symphony, but the two programs are...
, Microsoft Office Word, WordPerfect
WordPerfect
WordPerfect is a word processing application, now owned by Corel.Bruce Bastian, a Brigham Young University graduate student, and BYU computer science professor Dr. Alan Ashton joined forces to design a word processing system for the city of Orem's Data General Corp. minicomputer system in 1979...
and WordPro.
Long words affect this score significantly more than they do the grade level score.
Flesch–Kincaid Grade Level
These readability tests are used extensively in the field of education
Education
Education in its broadest, general sense is the means through which the aims and habits of a group of people lives on from one generation to the next. Generally, it occurs through any experience that has a formative effect on the way one thinks, feels, or acts...
. The "Flesch–Kincaid Grade Level Formula" translates the 0–100 score to a U.S. grade level, making it easier for teachers, parents, librarians, and others to judge the readability level of various books and texts. It can also mean the number of years of education generally required to understand this text, relevant when the formula results in a number greater than 10. The grade level is calculated with the following formula:
The result is a number that corresponds with a grade level. For example, a score of 8.2 would indicate that the text is expected to be understandable by an average student in 8th grade (usually around ages 12–14 in the United States of America). The sentence, "The Australian platypus is seemingly a hybrid of a mammal and reptilian creature" is a 13.1 as it has 26 syllables and 13 words. This page has the score of 12.1.
The lowest grade level score in theory is −3.40, but there are few real passages where every sentence consists of a single one-syllable word. Green Eggs and Ham
Green Eggs and Ham
Green Eggs and Ham is a best-selling and critically acclaimed book by Dr. Seuss, first published on August 12, 1960. As of 2001, according to Publishers Weekly, it was the fourth-best-selling English-language children's book of all time....
by Dr. Seuss
Dr. Seuss
Theodor Seuss Geisel was an American writer, poet, and cartoonist most widely known for his children's books written under the pen names Dr. Seuss, Theo LeSieg and, in one case, Rosetta Stone....
comes close, averaging 5.7 words per sentence and 1.02 syllables per word, with a grade level of −1.3. (Most of the 50 used words are monosyllabic
Syllable
A syllable is a unit of organization for a sequence of speech sounds. For example, the word water is composed of two syllables: wa and ter. A syllable is typically made up of a syllable nucleus with optional initial and final margins .Syllables are often considered the phonological "building...
; "anywhere", which occurs 8 times, is the only exception.)
Further references
- Kincaid JPJ. Peter KincaidJ. Peter Kincaid is a scientist and educator who is the founding director of the Modeling and Simulation Ph.D. program at the University of Central Florida. Trained as a human factors psychologist at the Ohio State University, Kincaid has split his career between higher education and working as a...
, Fishburne RP Jr, Rogers RL, Chissom BS (1975). "Derivation of new readability formulas (Automated Readability Index, Fog Count and Flesch Reading Ease Formula) for Navy enlisted personnel]". Research Branch Report 8-75, Millington, TN: Naval Technical Training, U. S. Naval Air Station, Memphis, TN.
External links
- Flesh — free-standing, Java-based, multi-platform Flesch–Kincaid Readability and Flesch Reading Ease Level tool.
- GNU Style and Diction — command line programs to calculate score
- PlainLanguage.com — All About Readability
- The Principles of Readability by William H. DuBay — a brief introduction to readability research