The comprehensibility of texts is particularly important in schoolbooks and non-fiction books. Already more than 40 years ago, Austrian textbook researchers found that most textbooks were written too difficult for the respective grades: Textbooks for grade 6 were as difficult as they could have been for grade 8.
Any size text can be analysed with TextQuest/ReFo, whole text or by paragraph.
After the analysis, you can display sentences that are too long or words that are too long, edit them immediately and then see what effect this has on the values of the readability formulas. Since each paragraph is analysed individually, you can immediately see which paragraph needs revision.
The results can be copied from the clipboard and processed further from there.