Collaborative concept mapping: provoking and supporting meaningful discourse

2. Ask students to represent the expected results of the designed experiments in a diagram.

3. Ask students to give an explanation for the nature of the relationships in their concept maps and represented in the diagram.

We have examined these ways of elaborating the concept-mapping task in two additional studies. In these studies, students could use a poster that was already structured and provided parts for the experiment, the diagram, and the explanation.

Because we asked students to construct a concept map first, and then to elaborate the relationships in the concept map, we could compare the student discourse that occurred during the construction of the concept map with the student discourse that occurred during the elaboration of it. As expected, the design of experiments and the drawing of diagrams elicited more interactions in which students related the electricity concepts to concrete phenomena and other forms of representation. The design of experiments also provoked the sharing of previously completed experiments and demonstrations in physics classes and the articulation of the idea of current consumption. We describe our experiences with the elaboration of the concept map in more detail below.

Articulation of misconceptions

During the design of the experiments, students often expressed the idea that an electric circuit uses up current, and that an intervention in the circuit affects only the part behind the intervention. In the following example, Winnie and Christine decided to draw an electric circuit with a piece of wood, because they hypothesized in their concept map that certain materials have a high resistance and, therefore, can't conduct current. Winnie's statements reflect the idea of current consumption or local reasoning, because she assumes that there will be a current between the battery and the piece of wood, but not between the piece of wood and the bulb.

Winnie: I think we have to measure current strength, but how can we do that?

Christine: I think the piece of wood has to be between the battery and the bulb; otherwise, we can't determine whether it conducts....

Winnie: Here (points) ... it's between the battery and the bulb.

Christine: Then we must connect these ones, because it results in....

Winnie: Yes, but look, when the current is going like this, then it doesn't come back, does it? When this does not conduct, it can't come back again.

Discussing other forms of representation

The task of designing experiments elicited student discourse about the way an electric circuit must be built and how it can be drawn using circuit diagram symbols (for example, a bulb is a circle with a cross). Many students referred to experiments that they had carried out previously in the physics class. This occurred, for example, when they were discussing how the physical quantities could be measured. When students tried to represent the expected results of the designed experiment in a diagram, they discussed how the quantities had to be represented in units and symbols and which variable had to be put on which axis.