Abstract:

It has become commonplace to note that children do not wait for their first science course before formulating explanations of the natural phenomena which they encounter in everyday life. Many studies of the teaching of science point out that explanations constructed by children as a result of their interaction with the material universe constitute a genuine improvement in relation to a stage of mental development as defined by Piagetian theory. However, these same studies suggest that these explanations are often erroneous relative to those constructed by the scientific community (explanations based on accepted scientific ideas). In the case of electrical circuit, many researchers investigated the conceptions of children aged 7 to 12 concerning a simple electric circuit (battery, wires and light bulb). They succeeded in showing that children -when asked to light the bulb using this apparatus - refer to erroneous models such as the unipolar model, the model of antagonistic currents and the attenuating model. One would normally expect that these naive explanations would disappear as the result of formal instruction on the working principles of a simple electric circuit. This is not at all the case, however. Numerous studies show that learners resort to spontaneous explanations whenever the context of the questioning differs from that of the problems at the end of the chapter in their textbook (Closset and Viennot, 1984). In the light of these results, we can appreciate the far-reaching importance for the teaching of electrical circuit of this kind of research. These investigations allow teachers to become acquainted with the explanatory models used by their students and to facilitate the transition from the sphere of naive conceptions to that of scientific concepts. The question remains, however, whether the discovery that the teaching of electrical circuit does not produce the expected results, and does not seem to help learners to conceptualize various electrical systems in an adequate way. A review of the international literature on this subject shows that a number of conceptual difficulties are induced, explicitly or implicitly, by the teaching tools proposed by educators. For example, studies of learners' conceptualization of complex electrical circuits show that the majority of conceptual difficulties are actually introduced in the teaching of these circuits (Métioui et al. 1995; Missonnier and Closset, 2004; Küçüközer and Kocakülah, 2007). The context of the present communication is thus provided by a number of studies of erroneous conceptions appearing subsequent to instruction. The conceptions of college students (N = 90) concerning Kirchhoff's laws are characterized. In the first section, we make explicit the limited conceptual framework in which Kirchhoff's laws are dealt with. In the second section, we describe methods used in our investigation: pencil-and-paper questionnaire. We also specify the characteristics of the target population. The mechanics of the design of the questionnaire are dealt with in the third section and the last section is devoted to an analysis of the experiment and its results. The results of the pencil-and-paper questionnaire show clearly that the application of Kirchhoff's laws, which express the basic behaviour of currents and voltages, presents for them an insurmountable difficulty, even in the simplest situations.

Keywords:

Student, hight school, conceptions, Kirchhof's laws.