In this paper we discuss some aspects related to the practical assessment of the quality of a grasp by a robotic hand on objects of unknown shape, based on sensorial feedback from tactile and force sensors on the hand. We briefly discuss the concept of contact and grasp robustness, pointing out that the former is an easily computable but overconservative sufficient condition for the latter. Some experimental results on a simple gripper, the so–called “Instrumented Talon”, are reported as an illustration.