Introduction: The familiar “qwerty” keyboard layout, originally designed for the mechanical typewriter, has been around since the later half of the 19th century. It survived the transition to the electronic computer keyboard and has become the standard way of entering text into a computer. However, when it comes to using it with a touchscreen, it has problems. This article discusses those problems and describes some research being done on a new method of text entry that is fast and tailored specifically to work with the touchscreen.
Problems with QWERTY: Recently touchscreen versions of the “qwerty” keyboard have appeared in smart-phones and tablets. These keyboards display a tiny version of the “qwerty” layout, named after the top left row of characters on a standard keyboard, and invite the user to tap one of the tiny keys to enter each character.
Any keyboard relying on pressing a separate key for each character, critically depends on the tactile feedback provided by the mechanical keys. When your eight typing fingers are placed above their “home” keys, you can feel the keys’ contours and thus can tell when your fingers stray from their home position. This frees your eyes for other things, like the text you might be copying or reading, or the person you are with. It also speeds text entry by eliminating the need for eye-hand coordination. Once the key positions have been memorized, i.e. once touch typing has been mastered, a “qwerty” keyboard can be quite fast.
This cannot be done with the touchscreen version of the “qwerty” keyboard because there is no tactile feedback. Because the screen is smooth, you can’t feel the keys. Even if you could, your fingers must be off the screen between key taps. To compensate, you must use your eyes to monitor the location of your fingers. This kind of eye-hand coordination is especially difficult with smartphones. Often the key images are tiny and are blocked from view by your fingers! Although the swiping keyboards, like Swype, can reduce the amount of finger movement, it still doesn’t eliminate the need for good eye-hand coordination.
As a consequence many tasks, normally done with a computer keyboard, are cumbersome with the touchscreen version. Copying text becomes particularly difficult in that your eyes must constantly jump between the text being copied and the keyboard. When in a meeting or classroom where notes are being taken, where a smartphone or tablet would really be handy, the same thing happens. The keyboard is also slow and error prone because of the eye-hand coordination needed to operate it.
There’s another Way: Although the touchscreen is clearly not well suited to emulating a typewriter or computer keyboard, there are many aspects of the touchscreen that lend itself to making a good text entry device. One of these is the ease of making swipes due to the screen’s smooth surface and the ability of the software to track the fingers’ positions. This has been demonstrated by the success of the pinch gestures pioneered on the iPhone.
To take advantage of this feature, what if each key press were replaced by a unique gesture? This would eliminate the need to constantly look at the input area since the gesture can begin anywhere.
More Fingers: One challenge with this approach, is devising enough, easy to make, unique gestures to allow for the 26 letters of the alphabet as well as some shifts and punctuation? One way is to use a small set of single finger gestures and combine them with multiple fingers to make possible a larger number of multi-finger gestures. Although more fingers could be used, three fingers were chosen here to be compatible with the smaller screens found on smart-phones. There are four unique combinations of three fingers:
- One finger by itself.
- Two adjacent fingers
- Two non-adjacent fingers
- All three fingers simultaneously
Now assume, when making a multi-finger gesture, all the fingers simultaneously do the same single finger gesture. One obvious single finger gesture is a simple tap where the finger comes up at the same place it goes down. Others are the four simple swipes: up, down, left, and right. Eight other gestures are curved swipes that start in one of the above four directions and end in another. This results in a total of 13 single finger gestures: one tap, four simple swipes and eight curved swipes. Combining these with the four finger combinations above, results in 52 unique three finger gestures. This is comparable to number of keys on a typical “qwerty” keyboard.
The frequency of use of letters and punctuation in English are then used to pair the most frequently used characters and shifts with the simplest to perform gestures to maximize speed. For example the fastest gestures, the four possible taps, are assigned to the “space”, “a”, “e”, and “t”, the most frequently used characters in English. To aid in learning the gestures, a table is shown under the fingers that tells you how to make the gestures.
Because the taps are very fast and the swipes only a few milimeters, text entry with this type of text entry can be fast. A three finger version has already been demonstrated at over 40 words per minute.
Summary: Although the standard “qwerty” keyboard, invented over 140 years ago, has been successfully used as a computer keyboard, it’s use with a touchscreen has serious limitations due to lack of tactile feedback. An attractive alternative to this is being developed in which each character is represented by a unique multi-finger gesture. This removes the need for eye-hand coordination and may finally make possible fast, eyes-free text entry on touch-screen devices like smartphones and tablets.