Fitt's Law
In the era of creative and slick computer user-interfaces, the revolving factor that all UI designers must consider is the end user's comfort and ease-of-use with the design. The user must be an active and involved part of the interface, not just a hapless by-stander. Thus, Fitt's Law plays the central role in determining the quality of user interfaces ; such as OS X and Windows. Moreover, the law is also intuitive ; yet no successful renditions of it are prevalent. Maybe, we need to give it more time.
