COMMENTS ON TEACHING INTRODUCTORY ELECTRICITY
(D.Psillos)
 

Martine Méheut
LDPES, Université Denis Diderot , Paris, France

The papers presented in chapters E3 and E4 bring to light the extent of the work underlying the design of teaching-learning situations. Taking into account the conceptions and reasoning of the students, closely connecting cognitive contents with problematic situations, and referring to scientific knowledge are the broad lines of the design of the sequences described .

Defining the cognitive objectives of the teaching-learning process, both researchers refer to scientific knowledge ; they try to characterize precisely the "distance" between scientific knowledge and the desired students' knowledge. So, in the sequence about electricity by D. Psillos, the choice of models to be taught is discussed with regard to both scientific models (relations between energy, voltage, intensity, resistance, time) and to the students' causal reasoning . In the sequences about the structure of matter, the desired models are defined with regard to students' conceptions and to specific features of scientific particle models (the "elementarity" of particles, the existence of vacuum in particular). One can remark that if the students' linear causal reasoning is taken as a constraint to be respected in defining the knowledge to be taught in the sequence about electricity, one aim of the second sequence concerning the structure of matter is to put students into a position to go further and to bring into play multi-variable reasoning. So students' reasoning is seen in the first case as a support for conceptual development, in the second case as an obstacle to go beyond (Viennot, unpublished).

For both authors, building concepts is seen as a long-term process, bringing into play more and more properties to adequately solve problematic situations ; elaborating questions and choosing the phenomena as objects of these questions are important aspects of elaborating these problematic situations. In the sequence "electricity", the main aims are the differentiation of the concepts of intensity, voltage and energy from an initial global notion "current/ energy" and the development of systemic viewpoints. In the sequences "structure of matter", the main aim is to elaborate more and more efficient particle models (in terms of predictive and unifying power), by addition of new properties (static, then kinetic and dynamic ones) to particles initially defined by a few invariable properties (shape and dimensions).

The epistemological references put into play seem not so different ; both authors consider scientific work as elaborating and using models as cognitive tools. So these projects can be included in a didactic research current which developed in close connection with the epistemology of models (see for example Martinand et al.1992, Méheut et al.1988, Méheut and Chomat 1990, Tiberghien et al. 1994, Tiberghien et al 1995 ).

The teaching-learning strategies make use of different "driving forces" : contradiction, analogy, unification. In the sequence D. Psillos presented, cognitive conflict is used for engendering a need for a better explanation ; it plays the part of a driving force for the desired learning process. In the sequences I presented, the justification appears rather a posteriori , as the "winning of a bet", in terms of unifying phenomenologies and increasing predicting capacities. Can these different viewpoints be linked to the concerned fields of physics , to the historical development of concepts in these fields ? Or are they the expression of some differences between the epistemological and psycho-cognitive individual roots of the researchers ?

The methodology of the research project developed by D. Psillos is developed in order to "monitor the conceptual evolution" of the students and to compare the effectiveness of the experimental sequence with the "usual" teaching with respect to the cognitive aims of the teaching-learning process. This methodological viewpoint is put into play also in the research project I presented ; the comparative character is somehow less systematic. Another type of methodology has been developed here, i.e. using the sequence as an experimental device to test hypotheses related to the part played by some problematic situations in the learning-process.

References

Martinand J.-L, Astolfi, J.-P., Chomat, A., Drouin, A.-M., Genzling, J.-C., Larcher, C., Lemeignan, G., Méheut, M., Rumelhard, G. and Weil-Barais, A. (1992) Enseignement et apprentissage de la modélisation en sciences. Paris : INRP.

Méheut, M., Larcher, C. and Chomat, A. (1988) Modelos de particulas en la iniciacion a las ciencias fisicas. Ensenanza de las Ciencias, 6, 231-238.

Méheut M. and Chomat A. (1990) The bounds of children atomism ; an attempt to make children build up a particulate model of matter. In P.-L. Lijnse, P. Licht, W. de Vos and A.-J. Waarlo (eds) Relating macroscopic phenomena to microscopic particles. Utrecht : CD- b Press.

Tiberghien, A., Arsac, G. and Méheut, M. (1994) Analyse de projets d'enseignement issus de recherches en didactique. In G. Arsac, Y. Chevallard, J.-L. Martinand and A. Tiberghien (eds) La Transposition Didactique À L'épreuve. Grenoble : La Pensée Sauvage.

Tiberghien, A., Psillos, D. and Koumaras, P. (1995) Physics instruction from epistemological and didactical bases. Instructional Science. 22, 423-444.

Viennot, L. (submitted to IJSE) Two dimensions to characterize research-based teaching strategies : the case of elementary optics in the french syllabus.
 

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SectionE, Comments on E4 from: Connecting Research in Physics Education
with Teacher Education
An I.C.P.E. Book © International Commission on Physics Education 1997,1998
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