Usability tests often present some real surprises where the participant's mental model does not match what they're presented with.

What are the biggest or most interesting surprises you've come across?



What was maybe the biggest surprise to me in the first few usability tests I conducted, that people really blame themselves when they're unable to complete a task on an obviously bad UI.

And I still like to be reminded how little people know about some domains. For example, how little people care about banking or telecommunications, how little jargon they understand and care to learn.

  • Good point. Abbreviations are another killer--when someone interprets what the letters mean incorrectly. Why should they know or care in the first place? – noluckmurphy Jul 23 '10 at 13:50
  • Wow...that's an interesting one. Possibly related to the fact that we (as in consumers) seem to have become trained to assume most software should be a) complex and b) buggy. We need lemon laws for software. – DA01 Jul 23 '10 at 14:03

I've always liked the one where the user can't move to the right place on the screen - because the mouse has reached the edge of the mouse mat.

  • @PhillipW: Has that actually happened to you? I've always wondered if this was a myth or an isolated incident. – Bryan Oakley Jul 26 '10 at 11:21
  • Yes. Although obviously its a computer newbie kind of error (kids or old people generally). – PhillipW Jul 26 '10 at 14:49

In my first usability study, both participants were convinced we were trying to sell them the software we were testing.

I was surprised how early you need stymie this concern in the recruiting process.


After a long, and rather baffling navigation of an ecomms site, where the user had been tasked with attempting to purchase a product, I had to ask them to think aloud to try and get a handle on their behaviour. Turns out he was looking for the phone number to call the company and buy the product over the phone!

It always amazes me how difficult some user groups find scrolling as well. I had a guy grapple to click and hold the bottom arrow on the browser scroll bar for ages with a shaky hand (due to the heart medication he was taking). He wasn't aware that he could move down past the page fold in any other way.

  • The story about the ecommerce site is interesting! – Allan Caeg Jul 23 '10 at 7:56
  • On occasion I've also reached for the phone because the site was THAT badly designed! (or the company was using plain old HTTP and not HTTPS) – AndrewJacksonZA Jul 23 '10 at 9:10
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    If there's actually someone there to answer it, I think its always good practice to have a phone number in the corner of the screen during an ecommerce buying sequence. It provides a fallback for people who have some tricky requirement which the website hasn't taken account of. – PhillipW Jul 23 '10 at 10:45
  • Seconded. A client of mine was very reluctant to put the phone number on the checkout pages -- the goal was to boost online sales -- but after a short trial, the results were very convincing. – Zoltán Gócza Jul 23 '10 at 12:32
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    A phone number AND an email address in case it is outside of business hours (timezones etc.) – AndrewJacksonZA Jul 23 '10 at 13:31

When users completely ignore error messages. They click OK and I'm trying to capture what happened.


In one of our usability sessions I asked the participant if they found the language selection drop-down helpful and she replied, "What would you need a language selector for? If you can't speak English you shouldn't be on the Internet!"

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    An opportune time to remind her that /Al Gore/ intended the Internet for everyone when he invented it. – danlefree Jul 24 '10 at 9:51
  • Am I right that you tested this in a country where English is not the primary language? Or did you test within the Spanish speaking community in the USA? – Raffael Luthiger Aug 14 '11 at 9:16

We had a guy who swore blind he had never heard of the site we were testing, didn't recognise the home screen etc. Turned out he used it daily, but always jumped in through direct links... Guess the branding wasn't so successful in the 1st version!

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