Textstat
Ruby gem to calculate statistics from text to determine readability, complexity and grade level of a particular corpus.
Table of Contents
- Usage
- Installation
- List of Functions
- Basic Functions
- Char Count
- Lexicon Count
- Syllable Count
- Sentence Count
- Average sentence length
- Average syllables per word
- Average letters per word
- Difficult words
- Advanced Formulas
- The Flesch Reading Ease formula
- The Flesch-Kincaid Grade Level
- The Fog Scale (Gunning FOG Formula)
- The SMOG Index
- Automated Readability Index
- The Coleman-Liau Index
- Linsear Write Formula
- Dale-Chall Readability Score
- Lix Readability Formula
- FORCAST Readability Formula
- Powers-Sumner-Kearl Readability Formula
- SPACHE Readability Formula
- Readability Consensus based upon all the above tests
- Basic Functions
- Contributing
- Development setup
Usage
require 'textstat'
test_data = %(
Playing games has always been thought to be important to
the development of well-balanced and creative children
however, what part, if any, they should play in the lives
of adults has never been researched that deeply. I believe
that playing games is every bit as important for adults
as for children. Not only is taking time out to play games
with our children and other adults valuable to building
interpersonal relationships but is also a wonderful way
to release built up tension.
)
TextStat.char_count(test_data)
TextStat.lexicon_count(test_data)
TextStat.syllable_count(test_data)
TextStat.sentence_count(test_data)
TextStat.avg_sentence_length(test_data)
TextStat.avg_syllables_per_word(test_data)
TextStat.avg_letter_per_word(test_data)
TextStat.avg_sentence_per_word(test_data)
TextStat.difficult_words(test_data)
TextStat.flesch_reading_ease(test_data)
TextStat.flesch_kincaid_grade(test_data)
TextStat.gunning_fog(test_data)
TextStat.smog_index(test_data)
TextStat.automated_readability_index(test_data)
TextStat.coleman_liau_index(test_data)
TextStat.linsear_write_formula(test_data)
TextStat.dale_chall_readability_score(test_data)
TextStat.lix(test_data)
TextStat.forcast(test_data)
TextStat.powers_sumner_kearl(test_data)
TextStat.spache(test_data)
TextStat.text_standard(test_data)
The argument (text) for all the defined functions remains the same - i.e the text for which statistics need to be calculated.
Installation
Add this line to your application's Gemfile:
gem 'textstat'
And then execute:
bundle
Or install it yourself as:
gem install textstat
List of Functions
Basic functions
Char Count
TextStat.char_count(text, ignore_spaces = true)
Calculates the number of characters present in the text.
Optional ignore_spaces
specifies whether we need to take spaces into account while counting chars.
Default value is true
.
Lexicon Count
TextStat.lexicon_count(text, remove_punctuation = true)
Calculates the number of words present in the text.
Optional remove_punctuation
specifies whether we need to take
punctuation symbols into account while counting lexicons.
Default value is true
, which removes the punctuation
before counting lexicon items.
Syllable Count
TextStat.syllable_count(text, language = 'en_us')
Returns the number of syllables present in the given text.
Uses the Ruby gem text-hyphen
for syllable calculation. Optional language
specifies which language dictionary to use.
Default is 'en_us'
.
Sentence Count
TextStat.sentence_count(text)
Returns the number of sentences present in the given text.
Average sentence length
TextStat.avg_sentence_length(text)
Average syllables per word
TextStat.avg_syllables_per_word(text, language = 'en_us')
Returns the average syllables per word in the given text.
Average letters per word
TextStat.avg_letter_per_word(text)
Returns the average letters per word in the given text.
Difficult words
TextStat.difficult_words(text, language = 'en_us')
Returns the number of difficult words in the given text.
Optional language
specifies which language dictionary to use.
Default is 'en_us'
Advanced formulas
The Flesch Reading Ease formula
TextStat.flesch_reading_ease(text, language = 'en_us')
Returns the Flesch Reading Ease Score.
The following table can be helpful to assess the ease of readability in a document.
The table is an example of values. While the maximum score is 121.22, there is no limit on how low the score can be. A negative score is valid.
Score | Difficulty |
---|---|
90-100 | Very Easy |
80-89 | Easy |
70-79 | Fairly Easy |
60-69 | Standard |
50-59 | Fairly Difficult |
30-49 | Difficult |
0-29 | Very Confusing |
Further reading on Wikipedia
The Flesch-Kincaid Grade Level
TextStat.flesch_kincaid_grade(text, language = 'en_us')
Returns the Flesch-Kincaid Grade of the given text. This is a grade formula in that a score of 9.3 means that a ninth grader would be able to read the document.
Further reading on Wikipedia
The Fog Scale (Gunning FOG Formula)
TextStat.gunning_fog(text, language = 'en_us')
Returns the FOG index of the given text. This is a grade formula in that a score of 9.3 means that a ninth grader would be able to read the document.
Further reading on Wikipedia
The SMOG Index
TextStat.smog_index(text, language = 'en_us')
Returns the SMOG index of the given text. This is a grade formula in that a score of 9.3 means that a ninth grader would be able to read the document.
Texts of fewer than 30 sentences are statistically invalid, because the SMOG formula was normed on 30-sentence samples. textstat requires atleast 3 sentences for a result.
Further reading on Wikipedia
Automated Readability Index
TextStat.automated_readability_index(text)
Returns the ARI (Automated Readability Index) which outputs a number that approximates the grade level needed to comprehend the text.
For example if the ARI is 6.5, then the grade level to comprehend the text is 6th to 7th grade.
Further reading on Wikipedia
The Coleman-Liau Index
TextStat.coleman_liau_index(text)
Returns the grade level of the text using the Coleman-Liau Formula. This is a grade formula in that a score of 9.3 means that a ninth grader would be able to read the document.
Further reading on Wikipedia
Linsear Write Formula
TextStat.linsear_write_formula(text, language = 'en_us')
Returns the grade level using the Linsear Write Formula. This is a grade formula in that a score of 9.3 means that a ninth grader would be able to read the document.
Further reading on Wikipedia
Dale-Chall Readability Score
TextStat.dale_chall_readability_score(text, language = 'en_us')
Different from other tests, since it uses a lookup table of the most commonly used 3000 English words. Thus it returns the grade level using the New Dale-Chall Formula.
Score | Understood by |
---|---|
4.9 or lower | average 4th-grade student or lower |
5.0–5.9 | average 5th or 6th-grade student |
6.0–6.9 | average 7th or 8th-grade student |
7.0–7.9 | average 9th or 10th-grade student |
8.0–8.9 | average 11th or 12th-grade student |
9.0–9.9 | average 13th to 15th-grade (college) student |
Further reading on Wikipedia
Lix Readability Formula
TextStat.lix(text)
Returns the grade level of the text using the Lix Formula.
Further reading on Wikipedia
FORCAST Readability Formula
TextStat.forcast(text, language = 'en_us')
Returns the grade level of the text using the FORCAST Readability Formula.
Further reading on readabilityformulas.com
Powers-Sumner-Kearl Readability Formula
TextStat.powers_sumner_kearl(text, language = 'en_us')
Returns the grade level of the text using the Powers-Sumner-Kearl Readability Formula.
Further reading on readabilityformulas.com
SPACHE Readability Formula
TextStat.spache(text, language = 'en_us')
Returns the grade level of the text using the Spache Readability Formula.
Further reading on Wikipedia
Readability Consensus based upon all the above tests
TextStat.text_standard(text, float_output=False)
Based upon all the above tests, returns the estimated school grade level required to understand the text.
Optional float_output
allows the score to be returned as a
float
. Defaults to False
.
Languages supported:
- US English
- UK English
- Catalan
- Czech
- Danish
- Spanish
- Estonian
- Finnish
- French
- Hungarian
- Indonesian
- Icelandic
- Italian
- Latin
- Dutch (Nederlande)
- Bokmål (Norwegian)
- Polish
- Portuguese
- Russian
- Swedish
Contributing
If you find any problems, you should open an issue.
If you can fix an issue you've found, or another issue, you should open a pull request.
- Fork this repository on GitHub to start making your changes to the master branch (or branch off of it).
- Write a test which shows that the bug was fixed or that the feature works as expected.
- Send a pull request!
Development setup
git clone https://github.com/kupolak/textstat.git # Clone the repo from your fork
cd textstat
bundle # Install all dependencies
# Make changes
rspec spec # Run tests