This paper motivates and presents a classification scheme for two-dimensional gestures in interactive systems. Most pen-based
systems allow the user to perform gestures in order to enter and execute commands, but the usage of gestures can be found
in other interactive systems as well. Much research so far has been focused on how to implement two-dimensional gestures,
how to recognize the users input, or what context to use gestures in.
Instead, the focus of this paper is to explore and classify interactive characteristics of two-dimensional gestures as they
are used in interactive systems. The benefits for the field are three-fold. First, such a classification describes one design
space for the usage of two-dimensional gestures in interactive systems and thus presents possible choices to system designers.
Second, empirical researchers can make use of such a classification to make systematic choices about aspects of gesture based
systems that are worth studying. Finally, it can serve as a starting point for drawing parallels and exploring differences
to gestures used in three-dimensional interfaces.