You Can't Judge Your Own Project
On the launch of the excellent Ticketstumbler site:
I don’t think the creator of an interface can ever objectively measure the usability of the interface, no matter how much they use it; they don’t ever have to learn it, because they created it in the first place.
I’m not saying usability is not the core. I’m saying that the creator of the interface is in no position to objective judge the usability because they have an innate knowledge of the system because they designed it and they know exactly how it functions and how it’s supposed to be used. If you want a real measure of usability, you have to get someone who understands the problem domain, but has never before seen your interface, and then objectively determine how easily they can figure out how to perform tasks and get things done. The fact that you, as the designer, already know exactly how the interface is built and operates precludes you from having an objective opinion of how easy the interface is to understand.
Similarly, a painting’s artist cannot objectively determine how beautiful/emotional/successful the work of art is, because he has an innate sense of what it is trying to convey to the viewers. Just because the artist sees the subtle details, nuances, allusions, etc, does not mean that other viewers will be able to glean the same information.
And to drive the nail home a third time, an engineer could not possibly be an objective judge of how easy a car is to operate (usability), because they already know where everything is and how it works. They need to have someone, without previous experience, sit in the seat to realize that putting the cigarette lighter and cup holders inside the center console is a bad idea and not at all intuitive…