Abstract: | This study explores the arguments used by 14-year-old students in making decisions about the design of a road in their area. The whole activity was based on an actual problem at the time the research took place. The procedure was a sequence, where students worked first individually, then in groups and finally they had to take a class decision. Then they had to realize one of the final proposals and design the construction of a bridge that their planning had involved. This paper first elaborates the general perspective of such an approach; it then describes the process of argumentation and analyses the nature of the students' arguments, which are discussed on the basis of a specifically constructed network. |