In this paper, we present a real world user study of 4 in- terfaces designed to teach new visual objects to a social robot. This study was designed as a robotic game in order to maintain the user's motivation during the whole experiment. Among the 4 interfaces 3 were based on mediator objects such as an iPhone, a Wiimote and a laser pointer. They also provided the users with different kind of feedback of what the robot is perceiving. The fourth interface was a ges- ture based interface with a Wizard-of-Oz recognition system added to compare our mediator interfaces with a more nat- ural interaction. Here, we specially studied the impact the interfaces have on the quality of the learning examples and the usability. We showed that providing non-expert users with a feedback of what the robot is perceiving is needed if one is interested in robust interaction. In particular, the iPhone interface allowed non-expert users to provide better learning examples due to its whole visual feedback. Fur- thermore, we also studied the user's gaming experience and found that in spite of its lower usability, the gestures inter- face was stated as entertaining as the other interfaces and increases the user's feeling of cooperating with the robot. Thus, we argue that this kind of interface could be well- suited for robotic game.