In usability testing we ask users to complete tasks and often ask them to rate how difficult or easy the task was. Does it matter when you ask this question? What happens if we interrupt users during the task instead of asking it after the task experience is over? Almost ten years ago researchers at
There are many helpful books on usability testing. It is also helpful to know what actually happens in usability tests, including what metrics people collect. I asked MeasuringU newsletter subscribers to answer a few questions about how they measure usability. Sign up for weekly updates at the bottom of this page. In addition to the
Have you ever watched a user perform horribly during a usability test only to watch in amazement as they rate a task as very easy to use? I have, and as long as I’ve been conducting usability tests, I’ve heard of this contradictory behavior from other researchers. Such occurrences have led many to discount the
If you compare the sigma value on this site with other values published in most six sigma literature, it’s important to know that a 1.5 σ “shift” is usually added. For example, if you see a sigma value of 1.08σ on measuringusability.com and want to compare it to other sources then add 1.5. The resulting
