The definition of good experimental methodologies is a topic of growing interest in autonomous mobile robotics. Recently, researchers in this field have started to recognize that their experimental methodologies have not yet reached the level of maturity of other disciplines. In the effort of improving the quality of experimental activities, some proposals have been made to take inspiration from how experiments are performed in traditional sciences. However, a comprehensive analysis of the peculiar features involved in the experimentation of autonomous mobile robots intended as engineering artifacts is, to the best of our knowledge, still lacking. In this paper, we aim at contributing to fill this gap by discussing experiments in autonomous mobile robotics from an engineering point of view. We start by considering autonomous mobile robots as technical artifacts, namely as physical entities designed for a technical function and provided with a use plan. Then, we show that, due to the nature of the field, scientific and engineering aspects are strongly interrelated in the experimental activities performed to assess and evaluate autonomous mobile robots. To make our discussion more concrete, we refer to some examples taken from the specific robotic application of search and rescue of victims after a disaster.