Charged poles?

A significant portion of the recent work in the field of physics education research has been concerned with the identification of alternate conceptions (Driver and Easley, 1978) that students have about physical systems. Most of this work has been concentrated in the area of mechanics. There has been some work done in the area of electricity and magnetism but, by comparison, this area has received relatively little attention. The author reports on a study designed to determine if student difficulties in understanding the interactions of electric charges with magnetic fields might be caused, at least in part, by an alternate conception. In discussions among physics teachers one often hears several reasons proposed for these difficulties. One reason given is that magnetic force situations are three dimensional. A second one is that the right hand rule is an unusual procedure which is often misunderstood. These matters are almost certainly involved, but might there not also be some alternate conception causing students difficulty? The purpose of the study was to determine whether the students thought of magnetic poles as exerting forces directly on electric charges, in a manner similar to the behaviour of electrostatic charges.