In some recent projects aimed at renewing the methodology for an integrated science, mathematics and computer teaching, where the introduction of educational robots in school may help to make learning more meaningful and motivating, some questions raise: what interest offers to introduce robotics in primary and secondary education? What is learned through the activities of Robotics? How to design experiences of "good learning" (constructivist) with robots? This paper attempts to answer the above questions, showing some discussions which compare the educational potential of LEGO Mindstorms environment for building and programming a physical robots with respect to LOGO softwares, with their virtual robot (the "turtle "). This analysis is conducted using as reference the "anthropological theory of didactics."