What user testing teaches us about writing for readers under stress
I recently came across an article about long sentences in government advice about COVID 19. The article was in The Conversation. The authors argued that 'Most government information on COVID-19 is too hard for the average Australian to understand.' The authors correctly identified complex sentences like this:
"Phase 3 will be subject to health advice, but will focus on continuing to build stronger links within the community and include further resumption of commercial and recreational activities.".
As the authors pointed out this is a complex sentence because of the number of words in this sentence (29 in total) and the formality of the language. In this example many of the words are also long - six have more than three syllables. The language used is also quite formal. As the authors of the article say, the last part of the sentence is better expressed as 'opening businesses and allowing some personal activities'.
Readers use their working memory when reading
When people read they rely on their working memory to understand the meaning of the individual words. Then they make sense of how those words fit together, going backwards and forwards at each key word. Logically, the more words in the sentence, the harder this is to do.
Stress reduces working memory
When the reader is under stress - worried about their health, or about the state of their business for example - they have even less working memory to devote to the task. So, by the time we get to 'recreational' in the sentence above, readers are tired. They have looked at each of the preceding words multiple times, and stored the meaning of each word in working memory, which is why readers typically spend longer looking at the last word in the sentence than they do those at the beginning. When users come across a word they are unsure of - say 'resumption' - they spend longer on that word and use up even more working memory.
Lists of bullets have the same fatiguing effect when they start with the same words as these do. Three of the bullets start with the word 'reopening'; and two with 'resuming'.
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