Essence.Readability.ari_score

You're seeing just the function ari_score, go back to Essence.Readability module for more information.

The ari_score method calculates the Automated Readability Index (ARI) of a given Essence.Document.

Details

The ARI uses two quantities, mu(w) and mu(s), where mu(w) is average number of letters per word in the given text and mu(s) is the average number of words per sentence in the given text. The ARI is then defined by the following formula: ari = 4.71 * mu(w) + 0.5 * mu(s) - 21.43

Commonly, the ARI score is rounded up and translated by the following table:

ARI scoreReadability LevelReader Age
1Kindergarten5-6
2First Grade6-7
3Second Grade7-8
4Third Grade8-9
5Fourth Grade9-10
6Fifth Grade10-11
7Sixth Grade11-12
8Seventh Grade12-13
9Eighth Grade13-14
10Ninth Grade14-15
11Tenth Grade15-16
12Eleventh Grade16-17
13Twelth Grade17-18
14+College18-22