Comment by DonHopkins

9 years ago

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.

[1] http://www.inference.phy.cam.ac.uk/dasher/

[2] http://www.inference.phy.cam.ac.uk/dasher/MobileDasher.html

[3] Dasher: information-efficient text entry: https://www.youtube.com/watch?v=ie9Se7FneXE

[4] Dasher Poem: https://www.youtube.com/watch?v=x-WLiY2p1LQ

3 comments

DonHopkins

Reply
rcarmo  9 years ago

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.

  • DonHopkins  9 years ago

    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]

    [1] http://www.yorku.ca/mack/chi2008b.html

    [2] https://www.youtube.com/watch?v=ie9Se7FneXE

    [3] https://www.youtube.com/watch?v=FFQgluUwV2U

    [4] https://github.com/xanxys/construct