Recognizers: $1  •  $N  •  $P  •  $P+  •  $Q  •  Impact of $-family
Tools: GECKo  •  GREAT  •  GHoST  •  AGATe

Screen shot from Mr. Spiff's Revenge, a video game
that uses the $1 recognizer and won the 2008
Dr. Dobb's Challenge for Best Windows Game.

Screen shot from Land Lines by digital artist
Zach Lieberman, which uses the $1 recognizer to help
explore satellite imagery. Liberman's blog describes
Land Lines and this video shows it working on a phone.

Impact of $-family

Gesture recognition can be difficult, arcane, and specialized. But it doesn't have to be. Published in 2007, the $1 recognizer, and the $-family recognizers that followed it, made gesture recognition easy to add to any user interface.

The $-family recognizers, of which $1, $N, $P, and $Q are canonical members, along with enhancements Protractor and $P+, have had significant impact on the use of gestures in interactive prototypes.

The $1 paper, published at ACM UIST 2007, is UIST's 4th most-cited paper of all time. Google Scholar shows the $1 paper being cited over 1100 times. Beyond citations, $1 has been implemented in hundreds of projects. Its use has gone beyond its initial intent for stroke-gesture recognition to things like hand-pose recognition.

The $1 paper and its siblings led to numerous follow-ons by other researchers, leading to the "extended $-family" of technologies. All adopt the same philosophy espoused in the original $1 paper: to take what are typically complex, arcane algorithms understood only by specialists and make them easy to convey, implement, and deploy on any platform for non-specialists whose objective is quickly enhancing interactivity. Accordingly, the $1 paper began a trend, followed by other $-family publications, of putting their entire pseudocode necessary for implementation directly in their papers.

Some of the core $-family publications were recognized with awards, including:

Beyond academic impact, $1 and the $-family have been rapidly absorbed into industry projects. For example:

The extended $-family

$1 and the other canonical $-family recognizers inspired other researchers to develop follow-ons that share the $-family motivation. In chronological order:

Some examples of the $-family in industry prototypes and projects:

The $-family recognizers have been used in industry prototypes and projects:

Some examples of the $-family in others' published research projects:

Many published research projects have used the $-family recognizers, especially $1:

$-family implementations by others

Over the years, many developers have sent in their own implementations of our $-family recognizers in various programming languages. We make no representations as to the correctness or completeness of these implementations, but offer them here "as is." (We also don't check these links very often, so some may have gone stale.) (Have one to add? Email wobbrock@uw.edu.)

$1

$N

$P

$Q


Copyright © 2018-2024 Jacob O. Wobbrock. All rights reserved.
Last updated July 14, 2024.