Models and Theories in Human-Computer Interaction/Fitts Law for Cell Phone Keyboards

Fitts law has become more and more important as new products are developed and especially new user interfaces requiring touch interaction. Fitts law is very important in considering the usability of mobile keyboards. There are many keys that need to fit on a small screen, all within close proximity to each other. The law becomes important when determining how far apart keys should be and where they are located. We can see that Apple has done many studies considering this law when creating their keyboards. On the iPad, users can split the keyboard into two to make it easier to type holding the iPad in both hands. On the iPhone, we can see that the keyboard can be changed to view more characters and the keyboard adjusts when just inputing numbers to make it easier to select keys.

Not too long ago, before smart phones, we had cell phones with physical keys that needed to be pressed and even had keys that needed to be pressed multiple times to get certain characters. Although, these buttons took more time to type with than single character buttons the arrangement of them seemed to fit well for most people and many could write text messages fairly quickly with them. If Fitts law isn't taken into consideration we would have a very hard time using our mobile keyboards and I'm sure we have all seen touch interfaces that provide very difficult to use keyboards.