Our haptic sense supplies our perception of body contact and motions, including texture and forces. Over the last ten years, "haptic feedback" has come to refer to many classes of robotic interactive devices which display to a user forces and textures computed from a virtual environment model, and transmit the user's physical actions back to the virtual environment via position and force signals.

Research has focussed principally on machine design and haptic psychophysics, solving important problems of display and perception. With the maturation of these areas, haptic feedback is becoming a viable design element for human-computer interfaces; yet we have little collective knowledge about how to employ it as such.

In this talk, I will

• Share insights gleaned from several years of using haptic feedback in an application design environment, and discuss when and how it can be used to best effect in interactive applications.
• Describe the unique attributes of the touch sense in physiological and psychological terms, and the nature of information and control that touching provides.
• Review where active touching helps, by setting forth the forms it may take and important parameters that describe it; and evaluate the specific benefits it offers to contemporary interface problems.
• Propose a simple interaction model that emphasizes holistic design principles, and highlights issues that arise in the process of creating specific haptic interfaces.