Clarity of Writing: Seeing Through The Fog

as Robert Gunning was an American pro-clarity, anti-jargon crusader who devised a simple way to measure the readability of a piece of writing. He named it ‘The Fog Index’.

It is a relatively simple way of being able to work out whether writing can be easily read or whether it is going to be heavy-going for the reader. A Fog Index of 13 or over could be an indication that the writer has made the task of reading too difficult for the reader. However, it should be noted, that the Fog Index is in essence a non-serious tool that should not be taken too seriously. It is fallible and should not be used as a template for your work.

This is how it works

1. Choose a passage from your work that is at least more than 100 words.
2. Count the number of words and then divide the total by the number of sentences, giving you the average sentence length. Rounding up or down if necessary. (If a long sentence contains two or more complete thoughts, treat each one as an individual sentence)
3. Count the number of words with three or more syllables. (Ignore proper names and words which become three-syllable only because -ed, -d or -es has been added to the basic word. )
4. Using a calculator (if need be) find the percentage of multi-syllable words.
5. Add your average sentence length to your multi-syllable words percentage.
6. Multiply that total by 0.4 to leave you the result of the Fog Index for that passage.

Below I will show three examples of the Fog Index at work. I have used some passages from some of my own work and I am just hoping the results are not too bad.

Example 1

From the article: The Spell Check and Some Potential Pitfalls

“/ When it comes to writing things it is important to always keep an eye on the way you are spelling things. / One good way to do this is to use a spell checker. / What could be simpler than pressing a button to check that you have spelt everything correctly? / But there is a problem with most spell checkers, they only check the spelling of each individual word, / so what you have written may be a word spelt right but it is the wrong word entirely. / It could be the case of an extra letter in a word, or maybe a letter missing. / Perhaps it is just that while typing you may accidentally have hit the wrong letter. / Shame that a spell checker will not have picked up on it. /”

Total words = 129

Over two syllables = 6

Percentage = 5%

Total sentences = 8

Average sentence length = 16

Adding 16 + 5 = 21. Multiply by 0.4

FOG INDEX: 8.4

In general terms, writing that is designed to be understood by a wide audience should be aiming for a fog index of 13 or less. For writing that should be near to universally being understood the fog index should be less than 8.

Example 2

From the article: Sectarianism is Still Rife in Scotland

” / Also, there has been the decline of the manufacturing industry which has meant the increase of the middle class and the increase in foreign ownership of companies in this country, / which makes them less likely to care about religion in the same way as home grown companies have done in the past. / There is also the fact that Catholics now hold positions of power in Scotland and are extremely well represented across the board in terms of employment, / mix that with the fact that there is a greater number of mixed marriages between people of different religious persuasions than there has ever been  and it all adds up to the reason why there has been a noticeable decrease, / but at the moment the problem still exists. / “

Total words = 126

Over two syllables = 16

Percentage = 13%

Total sentences = 5

Average sentence length = 25

Adding 25 + 13 = 38. Multiply by 0.4

FOG INDEX: 15.2

I suppose I should be hanging my head in shame just now as this one has failed the test. Of course, considering it was on a more serious subject and aimed more at a certain object, there was always going to be the likelihood of hitting a high number in the Fog Index.

Example 3

From the short story: Walking On Home

” / Someone shouted loudly that he had some drinks at his house and we were welcome to go back to his. / A few took him up on his offer, myself included. / We strolled up the road towards the house where more drink awaited us. / The air was not too cold considering it was still winter and it was after midnight. / Perhaps it was the influence of alcohol on the body that was shielding us from the cold, / perhaps the intoxication meant we did not feel it as bad as it was. / It was with some relieve, however, when we arrived at our destination, the warmth of indoors was inviting; / the chance to lose the jackets again, relax and chill, have a drink and continue the joviality of earlier. / “

Total words = 127

Over two syllables = 5

Percentage = 4%

Total sentences = 8

Average sentence length = 16

Adding 16+ 4= 20. Multiply by 0.4

FOG INDEX: 8

Conclusion: As a writer I was actually quite surprised but yet somewhat pleased with the results I found there. Of course the Fog Index itself (as noted above) is fallible and shot not be taken to seriously. For fun though it was good to see just how much clarity was in the writing; according to the Fog Index that is.

Other work by this author:

How Important Is Spelling And Grammar

The Spell Check and Some Potential Pitfalls