Tuesday, April 26, 2011

A-Z Challenge V = Visibility Zero

The Fog Index. Many of you will know all about this having attended "how to write clearly" courses. I suppose it mostly concerns official, business writing but I also think it can affect any writer.


Premise number one for all writers: who are we writing for? Intellectuals? Will they impressed by four-syllable words? Long sentences? If the answer's yes, then I suggest you go straight onto the next blog. But if your goal is to write crisply and clearly then read on...



The Fog Index was invented by an American anti-jargon activist, Robert Gunning


In my opinion, it's only a guideline, not a rule of thumb (who likes those anyway? Kick them out the door for a start), so - as in all of your writing - take this advice as you feel like it:


This is how it works:

  1. Choose a piece of written work which is at least 100 words long. Count the number of words.
  2. Divide the total by the number of sentences, which will give you the average sentence length.
  3. If a long sentence contains two or more complete thoughts (such as those separated by commas, colons or semi-colons) treat each thought as a separate sentence.
  4. Count the words of three or more syllables (not proper nouns or those compound words: caretaker, antisocial, transatlantic).
  5. What's the percentage of multi-syllable words (divide the number of multi-syllable words by word total and multiply by 100)?
  6. Add your average-sentence-length figure to your multi-syllable-percentage figure. Multiply the total by 0.4.
Are you still with me? Use a calculator! :)


The result is the FOG INDEX for that piece of writing.


A Fog Index of 13 or over means you have a heavy-going reading passage.


Have fun!