In engineering education many concepts are complex, and the student has to move between different representations. In electric circuits these representations are for example: graphs, mathematical models, drawings of circuits and the real circuits. The learning of a complex concept is a learning of a whole, consisting of as well single concepts as the relations between them. In our research we have found that exploring the relationships - links - between these different representations is of uttermost importance.
The links are not there just to learn, but have to be made by the students. As we have continued our work on how students make links between the different islands of single concepts, in order to make a whole of the complex concept, we have noted that the links between the islands are of different kinds. We will here discuss what kinds of relationships these links consist of, and how they differ in ways of coping with them for students, and how the teachers may notice and highlight these relationships in their instructions.