essence v0.2.0 Essence.Readability
The Readbility module contains several methods for calculating the readability scores of a text.
Summary
Functions
The ari_score method calculates the Automated Readability Index (ARI)
of a given Essence.Document
Calculates the Dale-Chall readability score. that provides a numeric gauge of the comprehension difficulty that readers come upon when reading a text. It uses a list of 3000 words that groups of fourth-grade American students could reliably understand, considering any word not on that list to be difficult
Gunning fog index measures the readability of English writing. The index estimates the years of formal education needed to understand the text on a first reading. A fog index of 12 requires the reading level of a U.S. high school senior (around 18 years old). The test was developed by Robert Gunning, an American businessman, in 1952.[1]
Calculates an estimate of the time it would take an average reader to read
the given Essence.Document, assuming a reading speed of 200 words per
minute
The smog_grade method calculates the SMOG grade measure of readability that
estimates the years of education needed to understand a piece of writing.
The SMOG grade is commonly used in rating health messages.
Please note that results for documents with less than 30 sentences are statistically invalid[1]
Calculates the speaking speed in words per minute, given a speech described
by the given Essence.Document and the recorded speaking_time in minutes
Calculates an estimate of the time it would take to read the given
Essence.Document as a speech, with a speaking speed of 120 words per
minute
Functions
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 score | Readability Level | Reader Age |
|---|---|---|
| 1 | Kindergarten | 5-6 |
| 2 | First Grade | 6-7 |
| 3 | Second Grade | 7-8 |
| 4 | Third Grade | 8-9 |
| 5 | Fourth Grade | 9-10 |
| 6 | Fifth Grade | 10-11 |
| 7 | Sixth Grade | 11-12 |
| 8 | Seventh Grade | 12-13 |
| 9 | Eighth Grade | 13-14 |
| 10 | Ninth Grade | 14-15 |
| 11 | Tenth Grade | 15-16 |
| 12 | Eleventh Grade | 16-17 |
| 13 | Twelth Grade | 17-18 |
| 14+ | College | 18-22 |
Calculates the Dale-Chall readability score. that provides a numeric gauge of the comprehension difficulty that readers come upon when reading a text. It uses a list of 3000 words that groups of fourth-grade American students could reliably understand, considering any word not on that list to be difficult.
| Score | Notes |
|---|---|
| 4.9 or lower | easily understood by an average 4th-grade student or lower |
| 5.0–5.9 | easily understood by an average 5th or 6th-grade student |
| 6.0–6.9 | easily understood by an average 7th or 8th-grade student |
| 7.0–7.9 | easily understood by an average 9th or 10th-grade student |
| 8.0–8.9 | easily understood by an average 11th or 12th-grade student |
| 9.0–9.9 | easily understood by an average 13th to 15th-grade (college) student |
Gunning fog index measures the readability of English writing. The index estimates the years of formal education needed to understand the text on a first reading. A fog index of 12 requires the reading level of a U.S. high school senior (around 18 years old). The test was developed by Robert Gunning, an American businessman, in 1952.[1]
The fog index is commonly used to confirm that text can be read easily by the intended audience. Texts for a wide audience generally need a fog index less than 12. Texts requiring near-universal understanding generally need an index less than 8.
[1] DuBay, William H. (23 March 2004). “Judges Scold Lawyers for Bad Writing”. Plain Language At Work Newsletter. Impact Information (8).
| Fog Index | Reading level by grade |
|---|---|
| 17 | College graduate |
| 16 | College senior |
| 15 | College junior |
| 14 | College sophomore |
| 13 | College freshman |
| 12 | High school senior |
| 11 | High school junior |
| 10 | High school sophomore |
| 9 | High school freshman |
| 8 | Eighth grade |
| 7 | Seventh grade |
| 6 | Sixth grade |
Calculates an estimate of the time it would take an average reader to read
the given Essence.Document, assuming a reading speed of 200 words per
minute.
The smog_grade method calculates the SMOG grade measure of readability that
estimates the years of education needed to understand a piece of writing.
The SMOG grade is commonly used in rating health messages.
Please note that results for documents with less than 30 sentences are statistically invalid[1].
Calculates the speaking speed in words per minute, given a speech described
by the given Essence.Document and the recorded speaking_time in minutes.
Calculates an estimate of the time it would take to read the given
Essence.Document as a speech, with a speaking speed of 120 words per
minute.