Originating
Person
|
Calculating Readability |
Readability research began in 1920’s |
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Gray and Leary (1935) |
5 key elements of the text: # of different hard words in a 100-word passage # of first, second, and third-person pronouns average sentence length in words percentage of different words # of prepositional phrases |
Rudolf Flesch (1948) “Flesch Readability Formula” |
Count words, syllables, and sentences in three 100-word passages. Reading Ease = 206.835 – 84.6 (total syllables/total words) – 1.015 (total words/total sentences) Results fall between 1 and 100, and the researcher looks it up on table (low numbers mean hard reading level; 64 is considered plain English). |
Robert Gunning (1952) “Gunning Fog Index” |
2 key elements (in 100-word passage): Average Sentence Length in words (asl) = 100/number of sentences (treat a fragment as a whole sentence) Hard Words (hw) = # of 3-or-more-syllable words/100 words (discount proper nouns, easy combinations like “newsletter”, familiar jargon, and verbs in which suffix –ed, -es, -ing forms the third syllable. GFI (grade level) = (ASL + HW) * 0.4 Online Calculator: http://gunning-fog-index.com/ |
Wilson Taylor (1953) “Cloze Procedure” |
Questioned assumption of above formulae that short words are easier to understand. In his procedure, the researcher deletes every x words (i.e., every 5th word) then gives the mutilated passage to a test group, who must fill in the blanks. Scoring is done by counting the number or percentage of blanks correctly filled in: the higher the number, the easier the reading. |
Automated Readability Index (ARI) (1967) |
Uses characters/word instead of syllables/word. A character is considered any letter, number or punctuation mark. The formula is: Grade Level = 4.71 (characters/words) + 0.5 (words/sentences) – 21.43 Online Calculator: http://www.readabilityformulas.com/free-readability-formula-tests.php |
G. Harry McLaughlin (1969) “SMOG - Simple Measure of Gobbledygook” |
Take at least 10 sentences in a row, count the number of words with 3+ syllables. Grade
Level = Ö number of words of at
least 3 syllables * (30/number of sentences) + 3 Online Calculator: http://www.wordscount.info/hw/smog.jsp |
Flesch-Kincaid (1975) |
Count words, syllables, and sentences in three 100-word passages. Grade Level = 0.39 (total words/total sentences) + 11.8(total syllables/total words) – 15.59 Online Calculator: http://www.standards-schmandards.com/exhibits/rix/ |
Merri Coleman and T. L. Liau (1975) “Coleman-Liau Index” |
Take any medium-length passage: Grade Level = (5.89 * characters/words) − (0.3 *
# of sentences in 100-word fragment) − 15.8 Online Calculator: http://www.readabilityformulas.com/free-readability-formula-tests.php |
Lexile Framework for Reading (1980s) |
Based on word frequency and sentence length. Results range from 0L to over 2000L, with higher numbers indicating more difficult text. The analysis is proprietary, but if you know a child’s lexile reading level or you want a book in a particular Lexile, you can use the site called “Find a Book”: http://www.lexile.com/fab/ |
Edward Fry (1988) “Fry Readability Graph” |
2 key elements (select three 100-word passages in book): average # of syllables in 100-word passage average # of sentences in 100-word passage Look up results on graph. |
Zakaluk & Samuels (1988) |
Based on 4 key elements: - two “outside the head factors” - text readability level - “adjunct comprehension aids” (i.e., subheadings) - two “inside the head factors” - word recognition skill - knowledge of the text topic |
Linsear Write Formula |
Developed by the US Air Force to analyze their technical manuals, this formula counts the number of “hard” (3+ syllables) and “easy” (< 2 syllables) words. The formula is: (# of easy words) + (3 * # of hard words)/number of sentences. If result is > 20, divide by 2 for grade level. If number is < 20, subtract 2, then divide by 2 for grade level. |
List of other readability calculations |
http://www.ideosity.com/ourblog/post/ideosphere-blog/2010/01/14/readability-tests-and-formulas |
Other online calculators |
http://www.readabilityformulas.com/free-readability-formula-tests.php (calculates: Flesch Reading Ease, Gunning FOG, Coleman-Liau index, Flesh-Kincaid Grade Level, ARI (Automated Readability Index), SMOG, Linsear Write Formula) |