Visual Similarity of Pen
Gestures:
Introduction:
Supporting
Pen Gestures is a desirable feature for user interface because it is fast by
means of specifying both operands and operation in one stroke. However, it is
difficult to design excellent gestures. Sometimes, gestures are hard to be
remembered by users. Sometimes, they are misrecognized by computers. The primary
contribution of this paper is to provide 22 possible predictors for similarity of
features obtained through gesture similarity experiments.
What are excellent features:
Similar operations with a clear spatial
mapping, such as scroll up and scroll down, should be assigned similar
gestures. Conversely, gestures for more abstract operations that are similar,
such as cut and paste, may be easily confused if they are visually similar.
Similarity Trial One:
The data
set of trial one consists of gestures that are varied widely in terms of how
people perceive them.
The
purpose of trial one is
(1)to determine what measurable
geometric properties of the gestures influenced their perceived similarity
(2)to produce a model of gesture
similarity. When given two gestures, the model could predict how similar people
would perceive those two gestures to be
After analysis, the following 22
possible predictors for similarity are given,
As
we can see from table 2, for this widely varied data set in trial one,
Curviness and Total Angle Traversed/Total length is most important in determine
the similarity of two gestures.
Similarity Trial Two:
The
purpose of trial two is exploring how systematically varying different types of
features would affect perceived similarity.
The data sets used in trial two are
as follows,
After analyzing the result of trial
two, the authors conclude that Log( aspect ) and density to be the main factors
in determine the similarity of two gestures.
Bibliography:
Long A C, Jr, Landay J A, etal. Visual Similarity
of Pen Gestures[D]. Berkeley, California:Department of Electrical Engineering
and Computer Science, University of California at Berkeley, April, 2000.
