STUDENTS UNDERSTANDING OF SUPERPOSITION OF ELECTRIC-FIELDS

In this article an analysis of the difficulties experienced by student s when applying the principle of superposition to electric fields is p resented. A study of university level students in France and Sweden re vealed the existence of difficulties arising out of two issues: (1) a causal interpretation of some relationships, (2) the student's need fo r an effect, motion of some kind, to accept the existence of a field. The links between these obstacles and a lack of a unified view on elec tric phenomena are discussed from a pedagogical point of view.