The first instantiation of the RAS-IFRR School on Robotics Science took place 19-23 July 2004 in Volterra, Italy. The theme for the first workshop was "human-robot interaction" (HRI), an interdisciplinary topic of significant current interest. The school, conceived as a high-quality international school to take place every summer, was organized as a full-week event at the recently renovated Dentro il Centro Studi. Given the theme of HRI, the school provided comprehensive coverage from fundamentals to applications of this emerging area. Tutorials on human-computer interaction, service robots in work and domestic environments, collaborative interfaces, cognitive modelling, multiple sensory modalities, humanoid robots are some of the topics discussed.