Typing is something you probably do every day, but it’s surprising how little we know about how we actually do it. Most people think that you need to have taken a touch typing course and learn how to use
all your ten fingers in order to type fast. But surprisingly we found that the number of fingers does not affect your typing speed. You could use only one or two fingers
per hand and still be very fast. For the first time we looked at how people move their fingers while they are typing in particular people who never took a typing course. To do that we used a so called motion capture system which has 12 high-speed infrared cameras that track the exact positions of 52 reflective markers on the hands and fingers. Entering text is a very fast process with only a fraction of a second between the key presses. But the motion capture data allowed us to
see exactly what finger presses which key and how the hands and fingers move in between the key presses. The most surprising things was that on average people that never took a touch typing course could type as fast as those that learned how to use all their 10 fingers. But it also turns out that people type very differently and develop all kinds of different strategies. To find commonalities between how people type, we looked at the so-called finger-to-key mapping, that is what finger they used to press a certain key, and looked at commonalities between these mappings. We found 4 different kinds of strategies for the left and 6 for the right hand. They ranged from just using the
index or middle finger of a hand up to a modified version of the touch typing system. But the interesting thing was really that for each of these groups there were people typing very slowly or very fast and all using the same strategy. In contrast to what you may expect, the number of fingers you use doesn’t make you fast at typing. Instead we found a range of other factors that can influence the performance. For example, fast typist more consistently used the same finger to press the same key every time. They also learned to keep their hands steady and not move them over the keyboard as much as slower typists do. If properly used, the touch typing system can still have some benefits. For example we found that touch typists looked at their fingers much less than untrained typists which is very useful when you’re doing complex editing tasks, for example. All this data will be openly available for other researchers to use. Studying such a basic activity such as text input is very important for the design of new user interfaces and can also help in developing new training methods or better support users.