Research interest in human-robot interaction (HRI) has been increasing in recent decades and has now reached an appealing degree of maturity, which encourages first steps toward a technology transfer from research centers to robot manufacturers. Making robots able to cooperate with humans in a safe and intuitive manner is no longer a futuristic vision but a concrete opportunity that is just around the corner. On the other hand, measuring the quality of this interaction is a novel field in robotics research and will be extremely useful for future assessments of all efforts in the direction of more effective HRI. First results exist, ranging from a simple approach, like the so-called "uncanny valley" proposed in [1], to a more scientific interpretation supported by physiological measurements [2]
