ABSTRACT
Input systems formalism is not recent. The pioneer work by Newman (1968) used a state diagram to represent a graphical system [Newman 68]. The seminal work by Bill Buxton in "A Three-State Model of Graphical Input" [Buxton 90] demonstrated that input devices, such as mouse, pen, single-touch, and similar ones, needed only three states to be described. Around the same time as Buxton's work, a well-rounded model for input interactions was published by Myers [Myers 90].
