We summarize methodological and experimental design issues related to three human-robot interaction studies investigating a drumming experience with Kaspar, a humanoid child-sized robot, and (in total 116) human participants. Our aim1 is not to have Kaspar just replicate the human's drumming but to engage in a 'social manner' in a call and response turn-taking interaction. This requires the set up of enjoyable as well as (as much as possible) controlled experiments. Two Human-Robot Interaction (HRI) experiments with adult participants and one experiment with primary school children were carried out to investigate different aspects of such interactions. We briefly summarize issues concerning experimental methodology and design, as well as ethical, legal, safety issues in addition to many 'practical' challenges of setting up and conducting HRI experiments with an autonomous humanoid robot.