In addition to Fitts’ Law, we (Schmidt, Zelaznik, Hawkins, Frank & Quinn, 1979) proposed a linear speed-accuracy trade-off. These two laws appear to be fundamentally different. We have begun a series ...

Redditor frendolargo used a principle called Fitts' law to organize his or her own Apple Watch — and followed up the experiment by posting the results in the Apple Watch subreddit. How thoughtful!

Coined by Paul Fitts in the 1950s, the law is applied to the location and size of menus and buttons in software. For example, a large button is faster to reach than a small one, and the edges of ...