The performance of a robot can be described in terms of many different parameters or characteristics. Their magnitude and relative importance vary depending on the inherent capabilities of the robot design and its intended applications. In general, a robot user would look for desirable characteristics such as high reliability, high speed, program-ability, and low cost. However, there may be trade-offs, between even these basic characteristics. For example, increasing the speed of the robot or lowering its cost may lead to lower reliability.