During our webinars and presentations, we often ask audiences to participate in a memory test. Here’s how it works: we put a slide containing a lot of words on the screen for 20 seconds. Then we take the slide away and ask everybody to write down as many words as they can remember. We’ve repeated this memory test hundreds of times over the years for audiences ranging from under a dozen people to several hundred. The results have been amazingly consistent. No matter where or when we do this, the vast majority of people are able to recall 5 to 9 words.
Psychologist George Miller’s research and Information Mapping’s Chunking principle
When the test is over, we thank everybody for participating—and for validating the work of cognitive psychologist George Miller. In 1956 Miller published a groundbreaking paper titled The Magical Number Seven, Plus or Minus Two in which he demonstrated that most people can hold 5 to 9 items in their short-term memory. Miller’s research findings led Robert Horn, the creator of the Information Mapping Method, to develop the Method’s first information management principle, the Chunking principle. This principle tells us to help readers understand and retain information by presenting it to them in chunks of 7 plus or minus 2 items.
Chunking information helps writers avoid building a “wall of words” on the web
Chunking your content is good strategy anytime, but it’s especially important when you’re writing for the web. Although nobody was thinking about writing for the web back in 1956, Miller’s work is more relevant today than ever before. Research has shown that reading online is much easier when information is presented in small, easily digestible chunks. The Chunking principle is simple and effective. It’s too bad so many people ignore it when they’re writing for the web, and don’t think about breaking up information into manageable chunks. When you create screen after screen of dense, featureless “walls of words” you’re building a barrier to communication that will quickly discourage visitors to your site. Applying the Chunking principle helps you work with, not against, the way your readers’ minds work. It’s an important step towards developing successful web content.
Jonathan's comment addresses another principle of Information Mapping, the Relevance principle. It's important that you chunk your content based on relevance. This supports user comprehension and recall.