WP Readability Analysis
WP Readability Analysis is a wordpress plugin that calculates the index of readability of a post or page using various methods: Gulpease, Gunning-Fog, Flesch and Flesch-Kincaid. With these formulas we try to analyze how difficult it is to read a text.
The method Gulpease, calibrated for the Italian language, unlike the other is based on word length in letters rather than syllables.
Methods Flesch-Kincaid and Flesch, who are the most famous, using formulas based on the average number of words per sentence and the average number of syllables per word.
The method Gunning-Fog uses a formula based on the average number of words per sentence and the percentage of words with 3 or more syllables.
Unlike Gulpease, these three methods are mainly used in the English language. Both Gunning-Fog that Flesch-Kincaid return a score which is the number of years of education that the user must have to understand the text.
I invite you to know more about the various pages of wikipedia devoted to the various formulas.