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The Magical Number Seven

It seems that almost every time I’m involved in designing a new user interface for an app or website, I inevitably bring up the magical number seven1. Although I’m using it in design terms, it’s origins are actually from a psychology paper published in 1956. It’s also commonly referred to as Miller’s Law2, which refers to both working memory and communications. It’s a simple concept about our working memory which you can read more at the Wikipedia page linked below in lieu of repeating it here. It’s also cited by the US CIA in Psychology and Intelligence Analysis3.

The reason I refer to the concept is generally in an effort to try and simplify user interfaces. I believe, as Miller had cited in his original paper, that anytime more options than needed are presented, the information becomes confusing. I like for any menu navigation item to contain less than seven options. I actually believe that closer to 3 is optimal and if you can fold the options out like a tree in steps of three you’ll get better results. Now, don’t get me wrong on this, I’ve built menus with 40+ items. Sometimes is necessary if you’ve got a directory of information that a user might want to try and navigate to a specific piece of information. This is also where search plays a vital role… or in the case of this website, I’ve playfully made the whole thing a maze of information. However, if you’re presenting the user with new information and trying to elicit an objective response to the stimuli, then my recommendation is to always limit the choices to seven or less. Some folks might cite the KISS (Keep It Simple Stupid) principle3 on this, but I think the Magical Number Seven is more appropriate to what’s really going on. I always try to present users with seven or less choices as to their next action. If you’re really only trying to get one single action from a user, limit the choices to one or none. I like to think of users as savvy and not just Pavlovian4 mouse clickers. That’s why I think it’s all about the magical number seven.

  1. https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two
  2. https://en.wikipedia.org/wiki/Miller%27s_law
  3. https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/psychology-of-intelligence-analysis/art6.html
  4. https://en.wikipedia.org/wiki/KISS_principle
  5. https://en.wikipedia.org/wiki/Classical_conditioning