A model of a virtual reality system created by MIT that plots three variables—autonomy, interaction, and presence—on a three-axis coordinate system. Autonomy describes the system's ability to receive and react to external stimuli, such as actions performed by a user. Interaction describes the extent to which all the commands present in the system are used by a user. Presence describes the extent to which the systems offers tactile feedback. Each of these variables is given a value between 0 and 1 and plotted on a three-axis coordinate system. The point at 0,0,0 would be no virtual reality while that at 1,1,1 would be the ultimate in virtual reality. See Virtual Reality.