The use of the simulation in the experimental groups The activity was performed in the physics lab, where a computer was available on each table. The students of the experimental group had used the simulation before in the same room. It was interesting to find out whether students, who were very familiar with the simulation, would realise that it could help them in their tasks. Therefore, the software was already loaded and ready to use, but the monitors were turned off and the teachers did not mention the simulation during the introductory presentation of the activity. It was decided to take a chance and to suggest the use of the simulation only if none of the groups asked for it during Task I. Once the computer was mentioned in a session, the simulation would become a part of the obvious environment for all the teams in the session.