User Testing Exposes Hidden Assumptions
Design is all about assumptions. If you don't assume anything how can you get started? Good design means getting those assumptions correct. Often times these assumptions will be wrong, and many of those assumptions will be hidden: the designer doesn't realize the assumption is being made. This is not a problem if the assumption is correct, but becomes an unknown problem if the assumption is incorrect.
Identify Assumptions with User Testing
One of the best ways to expose those hidden assumptions is through user testing. You can't fix something you don't know is broken. That is what makes User Testing so powerful.
To see an example of how user testing can expose hidden assumptions watch the screencast "A Lesson Learned in Accessibility" at CSS Tricks. If you are like me you would have assumed the same things about how screen readers work and how visually impaired users will use your site.
Some Hidden Assumptions
Here are some assumptions that I have unknowingly made in the past. Some of these are pretty obvious usability issues. Some of them are more subtle and were made very obvious during user testing.
- My users mostly use this version of Browser X.
- The input validation is sufficient.
- My users have flash installed.
- The order of my html doesn't matter.
- My users will read this block of text.
- This functionality meets the needs of my users.
- My users have this purpose when visiting my site/using my product.
- This feature is important to my users.
- This interface element is clearly understandable.
- My users will scroll to the bottom of this page.
- The information architecture of this site is correct.
- My users will fill out these fields in this order
- The state of the application is clearly indicated.
- My users will navigate the page using a mouse.
- The application will be used generally in the way it was intended to be used.
- My users don't need this feature.
- This affordance is recognizable.
The Biggest Assumption of All
The biggest assumption is the meta-assumption: I know what I am assuming and am correct about those assumptions. No matter how many usability tests you do or how much experience you have there is always another assumption you won't realize you have made. That is, until it becomes very obvious during user testing.
What are your hidden assumptions?
What assumptions have you made and how were they made obvious? Please share your stories in the comments below.