CHILDREN'S CONCEPTIONS OF ELECTRIC CIRCUITS: THE ROLE OF CAUSALITY

Research on the misconceptions that children hold about simple electric circuits indicate a difficulty to conceive an electric circuit as a system where element are acting concurrently rather than sequentially (Missonnier and Closset, 2004). Research conducted in many countries with children aged seven to thirteen, uncovered models they used for the functioning of simple electric circuits. When asked to light a bulb given a battery, bulb, and a length of wire, children typically created “unipolar” models. These “unipolar” models connected one part of the battery to one part of the bulb and described “flow” of electricity as moving from the battery to the bulb. These “unipolar” models rest on underlying linear causal connection between battery and the bulb. In a linear causal model, one thing causes another thing to happen in a temporal precedence. Anderson (1986) explained the preeminence of the rule of cause and effect in human as derived from our most primitive experiences of causation. At a very early age, children learn to expect a dynamic in which their actions impact an object such as toys, blankets, bottles. Anderson claims that this underlying pattern of thinking is manifest in students' conceptions in a variety of science problems. Research on conceptual change has shown that students' intuitive causal explanations may conflict with formal teaching and prevent the development of scientific understanding if these spontaneous conceptions are not acknowledged (Posner et al. 1982, Stepans, 2008). In this communication, we present the result of our study, on the nature of causal factors involved in children's explanatory models about electric circuits. One hundred four children (aged 10 to 12) from three elementary schools in urban areas in Nova Scotia (Canada) volunteered in the study were asked to solve simple problems and provide an explanation of their reasoning. The written questionnaire of one hour duration consisted of three questions, each comprising two parts: a multiple-choice part and an essay part. All three questions were designed to reveal incorrect and correct knowledge likely to represent the type of model that elementary students hold for electric circuits. Accordingly, the first question aimed at eliciting the student's notion of an electric circuit, the second question was intended to determine their notion of the motion of the factors involved in the phenomenon of light and finally the purpose of the third question was to verify their conception of the conservation of current. The findings reveal that these children used causal rules with various levels of complexity : a simple linear model where a battery causes a bulb to light up, a complex linear model where departing from a battery, meet in the bulb to create light and a cyclic model where the current moves around the circuit to keep the bulb lit up. Understanding the underlying causal assumptions of children's models for electric circuits may help teachers design activities to reduce children's conceptual difficulty in conceiving the systemic nature of electric circuits.