Usability Tip #2: When in Doubt, Don’t Assume the User Knows

I recently encountered one of the most entertaining articles/videos I have seen in a long time. And it can be applied to a couple typical usability questions that come up on every client project: 1) can we assume the user is going to know this piece of information that they need to understand the site; and 2) can we assume they will definitely see and use this part of the interface? These questions could be about something as simple as expecting that a user knows what an acronym means or something as complex as expecting that most users know how to work data filters.

Well, I’m here to tell you that, most of the time, if you even are asking the question and debating it, then it is probably safer to assume that the user doesn’t know. The great article/video I am referring to above is the Invisible Gorilla Video and I encourage you to have a look at it and the video and then return to the blog.

-don’t worry-we’re waiting patiently for you

Now, to be honest, the first time I saw that video, I did not notice the key figure that is the subject of the video. Quite amazing. Be sure to think about this video the next time you want to assume that a user is going to notice something in your interface that isn’t blatantly obvious.

Now, if that was not enough for you, there are a couple other tidbits from usability guru Jakob Nielsen. The first was a study where users were asked, quite simply, to run a Google search. 25% of people failed this task. Many of them completed some kind of search, but 25% did not complete a Google search. I know-it’s very hard to believe but true.

So, the next time you are asking yourself “well, the users must know X, Y, or Z” be sure to think of gorillas and Google. Your site will be all the more user-friendly as a result and your users will be happier as well.

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About Scott

Scott Barnard is the founder of The Usability Review and After earning 2 degrees from MIT, he transplanted to the San Francisco Bay Area where he had a front row seat to the dot com boom and bust and the subsequent growth in importance of web, mobile and desktop application designs to the everyday activities of businesses and consumers alike. Get in touch with Scott if you'd like to hire him to consult on web, mobile app, or desktop application design at
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