Introduction

Abstract

Pointing with the hand is an activity so basic and pervasive to human experience that most of us fail to notice the complex neural and psychomotor functioning that makes it possible. But pointing is more than neuromuscular events: it is the expression of our focus of attention on a particular aspect of the world. Pointing is inherently the communication of our intentions to other people. It is a demonstrative activity. It is with this sense that the, somewhat peculiarly named, computer input devices — the mouse, the joystick and the trackball — have become known as pointing devices. In a highly interactive system with a graphical user interface (GUI), the act of pointing is an act of communication with the system. Computer-based pointing is an expression of human intention that selects objects and actions mutually ‘known’ to the human user and the program.