Voltage presented as a primary concept in an introductory teaching sequence on DC circuits

The introduction of the voltage concept at the secondary school level is of particular importance. The learning of this concept is considered as very difficult. Here we present the content of a teaching sequence introducing voltage as a primary concept. The process of elaboration of this content is discussed. In our approach the concept of voltage is used as reference, and we analyse the essential steps of a voltage model. This voltage model was developed by taking into account not only pupils' views before instruction but also their reactions during and after teaching.