De-fog Your Prose Using Readability Metrics

- Nandini Sridharan

Trivia: Did you know that the readability and usability of technical documentation is significantly determined by the D & D factors? Wondering what the Ds are? They are nothing but Density and Diction of your prose. While the first is quite popular, the latter refers to the choice of words used in your writing.

Most writers often go the extra mile and some even jump loops to ensure that the write up appeals to the users by presenting a technically lucrative and accurate content. But in reality, what really makes the difference is what you write & how you write. If you are wondering, “isn’t this what I too have been saying”, then it simply means your peers who review your documents have to go beyond “instincts” and start practicing mathematical or scientific approaches to measure the effectiveness.


The fog index formula is as follows:

0.4 ((words/sentence) + 100 (complex words/words))

The fog index score ranges from 6-17 (starting from easy to difficult level).

In general, the fog index for a wide audience should be less than 12. 

Similar to this, there are other formulas, such as SMOG index, Coleman Liau index and Automated Readability Index (ARI), Flesch-Kincaid Index which can be adopted to your content based on the business or the domain needs.

In a nutshell, the metric system is meant to be used as a quantitative measure and an indicator of possible modifications to your content while retaining the essence of context. There are some automated web tools to calculate the readability score based on the above formulas. The common goal of each of these formulas is the same—predict and provide feedback on the clarity and conciseness of the content.

A wise man once said, “Writing is a labor of love”. If you feel so too, your work will testify the pride of your workmanship!

About the Author

Nandini Sridharan is a Senior Information Developer at Riversand, Bangalore. She is an experienced UX writer and has a flair for writing/designing contents for app products.