Robots are both fascinating objects for the general public and devices whose conception, understanding and pro- gramming involve many fields. This unique combination makes them an ideal tool for introducing science and technology to children. This paper presents the outcome of a programming workshop held on the occasion of the 2011 EPFL Robotics Festival. This workshop introduced programming using the robot “Thymio II”. The participants enjoyed this workshop very much, and their attitudes suggest that the public is attracted to such events out of interest rather than pure fun or educational concerns. Children appreciated the supervision, characterized by a high staff-per-child ratio of 1/3. We also show that in an hour of tutorial, children were able to acquire concepts such as the sensor or the loading of a program on the robot because they practised these enough. More theoretical and less practised concepts, such as the sensory-motor loop or the programming details, were not well understood. These findings now enable us to create better edutainment material.