Typing Performance is a function of Finger Agility.
When we try controlling our fingers – the typing speed is at least 5X slower, comparing to the automatic typing. Therefore, our goal is to think less of the keys, and to let our fingers type autonomously.
The more we try to control our focus on the keys – the poorer our typing performance will be.
Have you noticed, that when people can type quickly the do not seem to be thinking about the keys. And this is the most profitable state to be in when you type.
The second we try to find a key on the keyboard, or try recallalling where it is – our focus degrades significantly.
Therefore, anything that can help us not look at the keyboard will help us greatly during typing.
Ultimately this idea was successfully implemented in the Keyboard Stencil approach, developed at the ViaTyping.