We emphasis ease of use, because software that is difficult use, isn’t used. Our goal is to allow our users (or our client’s users) achieve their goals with effectiveness, efficiency and satisfaction of use. Or, more simply, we want our users to be able to do what they want to do with minimal fuss and difficulty.
We measure success first by the ease with which a user can master an application; a good user experience (UX) is one where the user can, from his or her first sight of the application, quickly understand how the application works and how to achieve his or her goals. The fact is that with applications, as with for people, first impressions do count, and getting that first impression right, is important to overall success of an application.
Secondly, we want the user to be able to complete their tasks easily. Whether it is booking a ticket for the theatre, or cancelling a visit to the dentist, the application should allow the user to proceed through the application in an intuitive manner, with all the information the user needs immediately at hand. To give an example, if the user is submitting a support request, and needs an account number to do this, then the account number should be available on that page; the user should not be forced to navigate elsewhere to find the number, scribble it down, and then return to the request page. This is, of course, basic stuff, but it’s still surprisingly commonplace.
Finally, users should be able to learn the application; that means that they don’t need to be repeatedly looking up how to do something (because the key stroke is CMD-Shift-Ctrl-2 or whatever!), but that the commands are obvious and memorable.