The Keyboard: RIP?

The keyboard is dead, or so a recent article in a UK tech magazine claims, following a discussion of keyboard evolution (including the recent Klingon edition). My maximum typing rate is 60wpm (touch typing), which is about double what I can achieve with pen and paper, though admittedly less than what I can achieve by just speaking. Obviously the context is going to have a noticeable effect. I can type the following line of programming source code faster than I can say it:

$www{$q[7](178)} = 'w';

Speech recognition has advanced to the point where transcription at normal dictation speed is possible. Touch-sensitive displays are available in all sizes, using a stylus for accurate pointing or fingers for general selection/movement. Pen gestures augment the input to provide the equivalent of shortcuts for common operations.

All very nice, but speech is a short-range broadcast technology, whereas the keyboard is point-to-point. That raises the probability of eavesdropping and communications noise in any environment where there are two or more speech interface users in close proximity. Open-plan cubicles, for example.

A typical finger tip covers one square centimetre when touching something. The same area on a typical LCD screen contains about 1500 pixels, and that figure is rising. A typical stylus is rounded at the tip, and can be detected with near-pixel accuracy (a pixel typically having a diameter of about 0.25mm). In real-world use, the limiting factors are most likely the visual acuity and pointing stability of the human user, especially as the finger or stylus must be positioned steadily and accurately above the ever-shrinking screen pixels. Unless, of course, all you want to do is select some rather large display object such as a button.

The finger tip covers too much of the screen for accurate pointing, hence the common displacement of the pointing focus to a few millimetres above where the screen is being touched, and sometimes the display of a zoomed view of the part of the screen being touched. The iPhone has such an interface.

The mouse, by comparison, can vary the pointer motion with respect to the mouse motion. Slow movements confine the pointer displacement to a few pixels, while faster motion will displace the pointer significantly more. This is possible without user confusion because the physical motion is remote from the pointer, unlike the stylus or finger tip which are both close to the part of the screen being selected thus restraining the pointer position to that of the finger/stylus.

It’s this kind of cold hard analysis that convinces me that the keyboard and mouse still have quite a lot of life left in them. Even the Klingons would agree.

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