Usability testing is a way to measure how well someone can actually use something for its intended purpose. Web site usability testing involves watching people try to actually use it.
Setting up a usability test involves creating a realistic scenario where the user can perform tasks that a typical user would do, while an obveserver watches and takes notes.
Four basic areas of usability are typically measured.
-Time on task: how long did it take?
-Accuracy: how many mistakes were made?
-Recall: how much did the user remember?
-Emotional response: how did the user feel?
Determine how well users can really use your site.