Checking text readability
What is a readability index? Readability refers to how easy it is to read and understand a text based solely on its own features. Readability can be measured using metrics such as the number of syllables...
Readability refers to how easy it is to read and understand a text based solely on its own features. Readability can be measured using metrics such as the number of syllables per sentence or the variety of words used, in order to calculate the 'level' and/or readability of a text.
Why do we need a readability index?
A readability index has many uses. A writer can use it to objectively assess the complexity of their work and determine whether it is written at a level appropriate for its audience. For example, a teacher can check whether their notes for pupils are really written at the pupils' level of education and whether they will be fully understood.
How to check the readability of a text?
Many formulas have been developed to check text readability, taking various parameters into account. In this article I present 2 popular formulas: the Flesch Reading Ease and the Gunning Fog Index.
Flesch Reading Ease
This formula aims to determine how difficult a text is to read, based on the result of a formula into which we enter parameters such as:
the number of words, the number of sentences and the number of syllables.
The lower the score, the more difficult the text is to read
| FOG value | Interpretation |
|---|---|
| 1-6 | very simple language, understandable even to primary school pupils |
| 7-9 | simple language, understandable to lower secondary school pupils |
| 10-12 | fairly simple language, understandable to upper secondary school students |
| 13-15 | fairly difficult language, understandable to undergraduate students |
| 16-17 | difficult language, understandable to master's degree students |
| 18 and above | very difficult language, understandable to graduates and people with higher education |
Gunning Fog Index
This index aims to determine how accessible a text is. Its value indicates the number of years of education needed to understand the text.
The formula, created for English texts, takes into account the number of difficult (i.e. long) words in the whole text. A difficult word is one with 3 or more syllables; in Polish, difficult words start from 4 syllables upwards. To apply this formula to Polish texts, we need to keep this rule in mind.
Calculating text readability with functions.
There are many libraries available online in various programming languages that provide ways to quickly calculate a readability index. One of them is py-readability-metrics, a Python module that makes it easy to determine the readability of a text.
https://pypi.org/project/py-readability-metrics/
Another option is the textstat library, which offers similar ways of checking text.
