Handwriting as Computer Interface

Pen Computers: Dream and Reality \Pen computers" [4] oer an interesting alternative to paper. One can write directly on a LDC (Liquid Crystal Display) screen with a stylus or \pen". The screen has an invisible sensitive matrix which records the position of the pen on the surface. The trajectory of the pen appears almost instantaneously on the screen giving the illusion of ink (\electronic ink"). Handwriting recognition allows text and computer commands to be entered. While nothing opposes the idea of a computer that would use multiple input modalities including speech, keyboard and pen, some applications call for a pen-only computer interface: in a social environment, speech does not provide enough privacy; for small hand-held devices and for large alphabet (e. g. Chinese), the keyboard is cumbersome. The dream is to have a computer that looks like paper, feels like paper but is better than paper. Currently, paper is the most popular medium for sketching, note taking and form lling, because it oers a unique combination of features: light, cheap, reliable, available almost everywhere any time, easy to use, exible, foldable, pleasing to the eye and to the touch, silent. But paper has also its drawbacks: in large quantities it is no longer light and cheap, it is hard to reuse and recycle, dicult to edit, expensive to copy and to mail, inecient to transform into computer les. With rapid technology progress, electronic ink could become cheaper and more convenient than paper, if only handwriting recognition worked! As of today, the mediocre quality of handwriting recognition has been a major obstacle to the success of pen computers. Users report that it is \too inaccurate, too slow and too demanding for user attention" [3]. The entire pen computing industry is turning its back on handwriting and reverting to \popup keyboards". On small surfaces,