Useability/ Useability Testing

Useability/ Useability Testing
Useability refers to the ease with which a user interface in a website can be used.

According to Jakob Nielsen, useability is important because "studies of user behaviour on the Web find a low tolerance for difficult designs or slow sites. People don't want to wait. And they don't want to learn how to use a home page. There's no such thing as a training class or a manual for a Web site. People have to be able to grasp the functioning of the site immediately after scanning the home page—for a few seconds at most."
Jakob Nielsen (1994), Usability Inspection Methods, Morgan John Wiley & Sons.

Useability can be improved by making web sites more efficient, tasks can be completed faster; easier to learn’ operation can be learned by observation; and making the page more visually satisfying to use.

Useability can be tested in 5 ways, outlined by Jakob Nielsen: Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
Efficiency: Once users have learned the design, how quickly can they perform tasks?
Memorability: When users return to the design after a period of not using it, how easily can they re establish proficiency?
Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
Satisfaction: How pleasant is it to use the design?