Clear writing – The Clarity Index

Clear writing – The Clarity Index  – for business communication


Have you noticed how some writing is terribly boring, or difficult to read and understand?

When it comes to writing, and speaking, simpler is better. The clarity index helps make writing easier to read and understand.

Long words and sentences make the writing more difficult to read. If we shorten the length of sentences and words, we can make the writing easier to understand and read. There is a difference between written and spoken English. If your writing is easy to read out loud it will normally have a great clarity index score. We tend to speak in shorter sentences, as we need to breathe. Many people forget this when they write.  In writing and speaking, simpler is better.

This index is based on word and sentence length. Select a sample of around 200 words, or less, then use the following formula: –

  1. Count the number of words and major punctuation marks (.,?, etc.)
  2. Divide the number of words by the major punctuation marks to find the average sentence length. (Target is +/- 15 words per sentence.)
  3. Add up the number of words that have three, or more, syllables.
  4. Divide the number of 3+ syllable words by the total of words, to determine the percentage of long words. (eg 35 in 200 is 17,5% – Target is+/- 15%)
  5. Add the two (2. And 4.)
  6. The sum is the index. (Target is +/-30)

The clarity of the document is in index = (Words / major punctuation marks) + ( 3+ syllable words/words)

Understanding the clarity index:

  1. Less than 20, the writing is probably too abrupt – too simple.
  2. Greater than 40, the writing is probably too complex for easy understanding. (think many AGM reports)
  3. Easiest to read is an index of around 30.

Try it for yourself …  Have a look at some of your emails, and the reports you have read or written.

Are they clear and easy to understand?

Clear writing tips Clarity Index

Start with the take-away in mind

The Clarity Index makes writing clear 

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Richard Riche

Change Communication and Employee Engagement specialist at One Clear Message Consulting
Richard specialises in helping you build real human communication skills. Employee Engagement / Experience, Emotional Intelligence skills, building high performance teams and a great place you want to work. TED style speaking and presentation skills. Training, consulting and coaching.
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