As a necessary precursor to complex multi-degree-of-freedom haptic display, we need to understand the issues that effect the stability of interaction with virtual environments. In Section 2, we will show that this issue is of fundamental importance in the development of a convincing haptic simulation of virtual environments. We will introduce the concept of "Z-width," and show that it is a useful performance measure for haptic manipulanda. In Section 3, we will review a set of experiments in which we have used a one degree-of-freedom device to gain an understanding of these issues, particularly with regard to the inherent mechanism dynamics. Section 4 will address the practical difficulties encountered in the low-frequency cancellation of physical damping. The specific goal of this project is to quantify, through theory and experimentation, some of the factors affecting the Z-width of a haptic display.