Readability: Making Text Flow
Engineer's 200-Word Sentence Sets New Record; Readers Still Lost at Word 47
Dear Marilyn: My sentences are grammatically correct. Why do people still complain they're hard to read?
— Grammatically Correct in Georgia
Dear Grammatically: Grammar is necessary but not sufficient. A grammatically correct sentence can still be a nightmare to read. The key requirements for readability are:
The Five Rules of Readable Sentences
1. Sentences must be well-formed syntactically
"This sentence no verb."
"This sentence has a verb."
Read your writing out loud. If it sounds wrong, it probably is.
2. Sentences must not exceed a certain length
"It is given as a rule, which however is not the only such rule you may encounter, that sentences should not exceed a desirable length of ten to fifteen words, never should fall below seven words or extend beyond the ultimate limit of tolerable length reached at twenty words, even though longer sentences may be found in high literature."
The Rule: Aim for 10-15 words. Never exceed 20. If you need more, break it into multiple sentences.
3. Sentences should not be too short either
"Sentences may be short. Then they are easy to read. And understand, too. But they look cheap. And breathless."
The Rule: Vary your sentence length. Mix short and medium sentences for rhythm. Human language is not a RISC instruction set.
4. Recursion must be kept to a minimum
"It is not easy to understand it when it is unclear what is referenced by 'it' – it by now should be clear what it is supposed to mean, isn't it?"
The Rule: Replace pronouns with actual names when ambiguous. A reader's mental "stack" is shallow—don't overflow it.
5. The choice of words should vary
"Using the same words all over to describe the same things again and again is not pleasant when we use the same words to describe the same thing."
The Rule: Use a thesaurus. Never use the same opening words in two consecutive sentences. Repetitive writing kills reader interest.
Quick Check
What is the recommended maximum length for a sentence in technical writing?