ABSTRACT
This paper presents a comparative study of cognitive mediations at work in the scope of pedagogical device dedicated to introduce robotic/computer science to learners of last section of kindergarten (5-6 years old). The device used for the experiment is a robot named «Blue Bot» and presents three modalities in the scope of proposed serious games: the body, the robot and digital tablet. This study highlights on how mediator-instruments influence the reception and learning of learners through their performances, strategies and conceptions built during programming activities. Beyond this observation, this contribution proposes to apprehend these differences taking into account specificities of the mediator-instruments and their gap from the learner physical reality.