Xerox PARC sued Palm over Graffiti for patent infringement in 1997 [1] [2], having filed a patent for Unistrokes in 1993 [3]. Their patent was ruled invalid due to prior art, Xerox appealed the ruling, and Palm payed Xerox $22.5 million [4]. Research [5] has shown Unistrokes to be somewhat faster than Graffiti.
>Furthermore, the [Unistroke] alphabet's strokes are well distinguished in "sloppiness space", allowing for accurate recognition of not-so-accurate input.
>Unlike Graffiti, Unistrokes gestures bare little resemblance to Roman letters. However, each letter is assigned a short stroke, with frequent letters (e.g., E, A, T, I, R) associated with a straight line. Unistrokes is analogous to touch-typing with a keyboard, as practice will result in high-speed, "eyes-free" input.
>Over twenty fifteen-phrase sessions, text entry speed in the Graffiti group increased from 4.0 wpm to 11.4 wpm. During the same time, text entry speed in the Unistrokes group increased from 4.1 wpm to 15.8 wpm. However, an analysis of variance yielded a lack of statistical difference in entry speed between the two techniques. Participants often performed unnecessary deletions, resulting in high correction rates. In addition, the duration of gesture chart views decreased quickly, but varied widely between participants. Inter-stroke time between the two groups was similar, but the significant difference in stroke duration favoured Unistrokes. The Graffiti alphabet's recognisability endears itself to novice users. However, this study shows that investing the same time learning Unistrokes can result in significantly faster stroke time and higher text entry speed.
Ken Perlin also developed a continuous stylus-based text entry system called Quikwriting [6] [7], which he patented [8]. And there have been various imitations and other questionable patents [9]. It would be interesting to measure how Quikwriting compares with Unistrokes and Graffiti -- it might be faster since it doesn't involve lifting the pen between letters.
Either way, Graffiti is still the best (most reliable and fast) pen input method I've ever used on a portable device by far, and it's ridiculous that we haven't caught up with it in 2016.
I'd love to have ACCESS do something with it other than a (pretty much dead) Android keyboard.
Many useful techniques are tied up in patents. But there are great free open source techniques too!
"Dasher" is another interesting text input technique: navigating through the library of all possible books, based on continuous pointing gestures plus language modeling, which alters the target size by the probability of the corresponding text, can be easily trained on any writing style, and automatically learns as you use it.
Unlike Graffiti-like gesture recognition systems, and like pie menus: inaccurate gestures can be compensated for by later gestures -- you can continuously and perpetually correct your errors without changing mode, canceling or repeating gestures. And it works seamlessly with any alphabet like Hiragana and additional characters without any extra learning.
I tried it a few times, ovar the years. It is very impractical, takes up a lot of real estate and requires you to look at what you're writing - something that is not an issue with Graffiti.
I suspect a major reason it's ridiculous something like Graffiti isn't widely available in 2016 is because of patents, FUD and NIH.
A text entry system that requires visual attention which you can't use while driving a car might be considered a safety feature. ;) Then again, it might just kill people faster who insist on texting while they're driving without looking at the road. ;( YOLO! BOOM
Dasher has different goals and trade-offs than Graffiti, so its useful for different kinds of applications, but it supports some very important features (like alternative alphabets, and language modeling) that are impossible for Graffiti to provide, which many applications require (especially Hiragana, constrained grammars, text messaging and chat with Unicode and emoji symbols, easy training, and accessibility for people with limited motion or alternative input methods).
The paper comparing Graffiti and Unistroke [1] measured Graffiti at up to 11.4 words per minute with a consistent 26% correction rate, and Unistroke at up to 15.8 words per minute with decreasing correction rate from 43% to 16%.
Dasher is faster and has a steep but easy learning curve (it's self revealing and doesn't require a reference card).
David MacKay described an experiment in his Google Tech Talk [2] that measured novice users performance over time. Bottom of the class started at 5 words per minute, and improved to 10 words per minute after an hour of practice; top of the class started at 12 words per minute, and got to 25 words per minute after one hour of practice.
Expert dasher users using a hands-free eye tracking interface have been measured at up to 25 words per minute with an error rate of essentially zero.
I also think Dasher would be quite useful and natural for head mounted displays, and that is a fruitful avenue for further research. [3] [4]
The really weird thing is that I can handwrite Traditional / Simplified characters stroke by stroke into my iPhone, but I can't do the same with English. How's that for stupid!
>Furthermore, the [Unistroke] alphabet's strokes are well distinguished in "sloppiness space", allowing for accurate recognition of not-so-accurate input.
>Unlike Graffiti, Unistrokes gestures bare little resemblance to Roman letters. However, each letter is assigned a short stroke, with frequent letters (e.g., E, A, T, I, R) associated with a straight line. Unistrokes is analogous to touch-typing with a keyboard, as practice will result in high-speed, "eyes-free" input.
>Over twenty fifteen-phrase sessions, text entry speed in the Graffiti group increased from 4.0 wpm to 11.4 wpm. During the same time, text entry speed in the Unistrokes group increased from 4.1 wpm to 15.8 wpm. However, an analysis of variance yielded a lack of statistical difference in entry speed between the two techniques. Participants often performed unnecessary deletions, resulting in high correction rates. In addition, the duration of gesture chart views decreased quickly, but varied widely between participants. Inter-stroke time between the two groups was similar, but the significant difference in stroke duration favoured Unistrokes. The Graffiti alphabet's recognisability endears itself to novice users. However, this study shows that investing the same time learning Unistrokes can result in significantly faster stroke time and higher text entry speed.
Ken Perlin also developed a continuous stylus-based text entry system called Quikwriting [6] [7], which he patented [8]. And there have been various imitations and other questionable patents [9]. It would be interesting to measure how Quikwriting compares with Unistrokes and Graffiti -- it might be faster since it doesn't involve lifting the pen between letters.
[1] http://www.brighthand.com/news/palm-xerox-finally-settle-gra...
[2] http://www.palminfocenter.com/news/8628/xerox-graffiti-lawsu...
[3] https://www.google.com/patents/US5596656
[4] https://en.wikipedia.org/wiki/Graffiti_(Palm_OS)#Lawsuit
[5] http://www.yorku.ca/mack/chi2008b.html
[6] http://mrl.nyu.edu/~perlin/doc/quikwriting/quikwriting.pdf
[7] http://www.mrl.nyu.edu/projects/quikwriting/
[8] https://www.google.com/patents/US6031525
[9] http://shr-devel.shr-project.narkive.com/wIClUJgX/someone-is...