1 + 1 = 3: Explaining Busyness and Background Noise on Websites

Post from January 18, 2007 (↻ December 13, 2022), filed under (feed).

This and many other posts are also available as a pretty, well-behaved ebook: On Web Development.

“1 + 1 = 3 (or more)” is an important design effect described by Josef Albers and Edward Tufte. It means that two elements in close proximity cause a visible interaction:

Two parallel bars that appear to create a third element.

Figure: 1 + 1 = 3. (Copyright Al Globus.)

This interaction can result in perceiving information that is not there. Beside having a negative because distracting and distorting impact on charts and graphics it can also, to use Steve Krug’s words, cause undesirable “busyness” and “background noise” on websites.

Therefore, “1 + 1 = 3” is one of the effects you want to avoid, at least be aware of, when creating graphs and designing websites. (Of course, a designer always wants to keep information design principles in mind.) Edward Tufte’s books are invaluable resources in this regard, and I recommend checking out the following excellent articles:

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About Me

Jens Oliver Meiert, on September 30, 2021.

I’m Jens, and I’m an engineering lead and author. I’ve worked as a technical lead for Google, I’m close to W3C and WHATWG, and I write and review books for O’Reilly. I love trying things, sometimes including philosophy, art, and adventure. Here on meiert.com I share some of my views and experiences.

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Comments (Closed)

  1. On December 2, 2008, 14:51 CET, Richard Morton said:

    It seems obvious when shown visually like that, and it is something that is used quite deliberately in personalising car number plates (registration plates).
    I assume that the problem is also made worse by the fact that people skim read so much of the web these days, so unless it is obviously two separate elements confusion can easily arise.