The automated readability index (ARI) is a
readability test for
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
texts, designed to gauge the understandability of a text. Like the
Flesch–Kincaid grade level,
Gunning fog index
In linguistics, the Gunning fog index is a readability test for English writing. The index estimates the years of formal education a person needs to understand the text on the first reading. For instance, a fog index of 12 requires the reading lev ...
,
SMOG index,
Fry readability formula
The Fry readability formula (or Fry readability graph) is a readability metric for English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ...
, and
Coleman–Liau index, it produces an approximate representation of the
US grade level needed to comprehend the text.
The formula for calculating the automated readability index is given below:
:
where ''characters'' is the number of letters and numbers, ''words'' is the number of spaces, and ''sentences'' is the number of sentences, which were counted manually by the typist when the above formula was developed. Non-integer scores are always rounded up to the nearest whole number, so a score of 10.1 or 10.6 would be converted to 11.
Unlike the other indices, the ARI, along with the Coleman–Liau, relies on a factor of characters per word, instead of the usual syllables per word. Although opinion varies on its accuracy as compared to the syllables/word and complex words indices, characters/word is often faster to calculate, as the number of characters is more readily and accurately counted by computer programs than syllables. In fact, this index was designed for real-time monitoring of readability on electric typewriters.
Notes
{{Readability tests
Readability tests