What Do We Mean by "Usable"? - IV

True usability is invisible. If something is going well, you don't notice it. 

If the temperature in a room is comfortable, no one complains. But usability in products happens along a continuum. How usable is your product? Could it be more usable even though users can accomplish their goals? Is it worth improving?

Most usability professionals spend most of their time working on eliminating design problems, trying to minimize frustration for users. This is a laudable goal! But know that it is a difficult one to attain for every user of your product. 

And it affects only a small part of the user's experience of accomplishing a goal. And, though there are quantitative approaches to testing the usability of products, it is impossible to measure the usability of something. You can only measure how unusable it is: how many problems people have using something, what the problems are and why. 

By incorporating evaluation methods such as usability testing throughout an iterative design process, it is possible to make products and services that are useful and usable, and possibly even delightful.