Change is Inevitable, but is it Invisible?

Created: Tuesday, 07 July 2015 Written by Gary Elsbernd Print Email

The internet is full of stories of a website making what they consider a small change, only to have their user base revolt, often leading to rolling back the changes.  Facebook is often attacked whenever they make any change to their timeline, layout, or even their logo.  While these changes are noticed and talked about ad nauseum, I recently read an article by Kathryn Whitenton from the Nielsen Norman Group about Change Blindness, which is the other end of the spectrum. 

But first, a magic trick:

 

Mentally, select a card and concentrate real hard on it…

Don’t click on it or even point at it though…let’s keep this difficult…

 

Change blindness is the tendency of people to overlook alterations in images, especially when those changes appear immediately after a visual interruption such as a flickering screen.  If your website reloads when the user clicks a button, a change to the menu, a notification or a secondary option can be easily overlooked.  If those changes are important to the user in performing the task, that change blindness can severely impact your user experience.

The factors that impact this effect are proximity to the user’s fixation point, interruption of our visual perception and speed.

  • Proximity – As the user works his or her way through the site, their fixation point moves.  If the change you make is in the menu, the header, or a notification that is away from where the user is focused, or worse yet, off screen, the chance of the change being noticed is low. I purposely moved the link to click away from the cards to increase that distance.
  • Interruption of visual perception – your vision is interrupted when a page reloads, when we blink, when our eyes are quickly jumping from one fixation point to another, or when a screen display shifts as a device reorients from vertical to horizontal presentation. I took advantage of the screen change to interrupt your visual perception.
  • Speed – Fast changes in visual details are more likely to be missed by even brief interruptions. The blink of an eye is typically 300-400 milliseconds; change blindness has been observed when an image is interrupted for just 67 milliseconds. With the refresh, the change was nearly instantaneous.

In reality, all of the cards from the first set were removed and replaced by similar cards. No matter which card you had chosen, it would have “disappeared.” The change blindness, however, caused you to miss the fact that all cards were gone and just focus on your card. 

How can we design for change blindness?

If seeing a change is important to the user experience or the user’s ability to successfully complete a task, you want to minimize change blindness.

  1. Make changes obvious – use color or size to draw attention to the change.
  2. Make changes close – ensure any changes to instructions, notifications, warnings, etc. happen inline or as close to the user’s interaction as possible.
  3. Make changes without a refresh or scroll. Instead of refreshing, switching pages or tabs or any other shift of context to reveal a change, work inside the page with AJAX calls.
  4. Slow changes down. A slower animation, such as a fade, can draw attention to a change on your screen.

And if you want to write me to complain that a good magician never reveals his tricks, remember I never claimed to be a good magician.  

“Change Blindness: Why People Don’t See What Designers Expect Them To See” Kathryn Whitenton, 2015.