Teachers’ insight into misconceptions about simple circuits Estelle Gaigher Department of Science, Mathematics and Technology Education, University of Pretoria, South Africa
[email protected] Abstract Many studies on learners’ misconceptions about electricity have been published internationally, but studies on teachers’ awareness of these misconceptions are few. This article reports on a case study to investigate to what extent South African teachers understand learners’ misconceptions about series and parallel circuits, and to what extent such understandings are integrated into their pedagogical content knowledge. Nine teachers from public schools were purposefully selected to participate in the study. Qualitative data were collected from questionnaires and interviews. It was found that teachers often indicate simple misconceptions as sources of learners’ mistakes, but that misconceptions related to incorrect analysis are seldom mentioned. Furthermore, it was found that these teachers’ knowledge about misconceptions was fragmented and not integrated with their understanding of basic concepts. The results indicate that these teachers display inadequate pedagogical content knowledge regarding misconceptions about series and parallel circuits. It is recommended that pedagogical content knowledge regarding misconceptions should be developed during teacher training. Keywords: misconceptions; electric circuits, teachers’ knowledge
This document is a translation of an article published in Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie. Please reference as follows: Gaigher, E. (2016). Teachers’ insight into misconceptions about simple circuits. SuidAfrikaanse Tydskrif vir Natuurwetenskap en Tegnologie, 35(1), 8 pages. doi: 10.4102/satnt.v35i1.1363
Introduction
It is generally known that learners regard electricity as a difficult subject. Since the early eighties, a lot of research has been done that shows that misconceptions about electricity are prevalent among pupils and students, regardless of culture (Cohen, Eylon & Ganiel 1983; Küçüközer & Kocakülah 2007; Shipstone 1984; Shipstone et al. 1988). From a constructivist point of view it is important that misconceptions are used as a starting point in teaching (Hammer 1996; Morrison & Lederman 2003). It is therefore important that teachers have knowledge of misconceptions and are able to recognise when pupils' errors arise from misconceptions. There is, however, a limited amount of literature available on teachers' awareness of misconceptions (Gunstone, Mulhall McKittrick 2009; Larkin 2012; Pardhan & Bano, 2001). If misconceptions are not corrected, they impede the concept development of the accepted scientific model. The present study aims to contribute to the literature by first examining the extent to which South African teachers understand pupils' mistakes on series and parallel connections as misconceptions, and second, how teachers integrate their knowledge of misconceptions with their own basic knowledge and insight about circuits.
Literature study
Misconceptions can be described as specific, stable, recurring patterns of thought that are not consistent with accepted scientific models, which leads to erroneous understanding and explanations of natural phenomena (Hammer, 1996). For example, a well known misconception in electricity is that current is consumed by resistors, with the associated erroneous prediction that current decreases as it moves through a circuit. Misconceptions arise from everyday experiences in reality as experienced by individuals and which have been processed into inappropriate models also known as alternative conceptions, preconceptions and children’s' science (Gilbert & Watts, 1983). It is important that teachers show insight into misconceptions so that the pupils' understanding of the scientific model may be developed (Larkin, 2012). Several studies have contributed to define a comprehensive set of known misconceptions about simple circuits (e.g. Cohen, Eylon & Ganiel 1983; Shipstone 1984). There exists an overlapping of different misconceptions, as well as different names for similar misconceptions. Sencar and Eryılmaz (2004) summarized common misconceptions as follows: the unipolar model; colliding currents; current weakening; current sharing; empirical model; local and sequential reasoning; the short circuit misconception; parallel misconception and the constant current source. Engelhardt and Beichner (2004) added the superposition model that describes a misconception about the linking of cells. Some misconceptions are extremely hardy and resist teaching. The unipolar model is easily overcome, while current weakening and the constant current source are the most persistent misconceptions that occur even among university students (Chambers & Andre 1997; Stocklmayers & Treagust 1996; Dupin & Joshua 1987). It was found that misconceptions can often be traced to poor understanding of potential difference, and a tendency among students and teachers to think primarily in 1
terms of electric current while voltage is avoided (Cohen et al. 1983; Liegeois et al. 2003; Tsai et al. 2007). The concept of phenomenological primitives is also used to describe faulty thinking patterns (DiSessa, 1993; Smith, Di Sessa & Roschelle 1993). As misconceptions, phenomenological primitives (p-prims) are also based on everyday life experiences, with the difference that p-prims represent generally applicable rules, while misconceptions describe specific topics and situations. Di Sessa (1993) describes p-prims as follows: ‘.... p-prims constitute the basic encoding of the naive sense of mechanism’ (p.203), i.e. a pattern that describes various phenomena. A well-known p-prim carries the name ‘Ohm’s p-prim’, but is certainly not limited to Ohm's law; Ohm's law is rather an example of this p-prim. The p-prim describes the relationship between an agent, an effect and an opponent: the stronger the agent, the greater the effect; and the stronger the opponent, the smaller the effect. This p-prim is a precursor to understand direct and inverse proportion, making it easier to understand physical laws like Newton's second law, and indeed to understand Ohm's law. However, this p-prim is applied incorrectly in cases where learners are not able to distinguish between agent, opponent and effect. The construct of pedagogical content knowledge (PCK) is used as a theoretical framework for this study. Shulman (1986) introduced this construct to promote the importance of subject matter in the study of education. Since then, the construct has grown to a field of study in its own right (see e.g. Kind 2009 for an overview). Shulman described PCK as the knowledge that a teacher can use to transform his own subject matter knowledge into a usable form that can be transmitted to pupils. In his description of PCK, Shulman points out that teachers’ understanding of learners’ prior knowledge and misconceptions is an important part of PCK. This aspect of PCK is is described as ‘knowledge of content and students’ in the PCK model of Hill, Ball and Schilling (2008). This PCK model separates pedagogical content knowledge from subject matter knowledg and describes PCK as consisting of three fields of knowledge, viz. knowledge of the curriculum (KC), knowledge of content and students (KCS) and knowledge of content and teaching (KCT). The latter two fields are of interest in the current study: KCS includes how teachers understand learners’ errors and misconceptions, while KCT includes the integration of teachers’ understanding of misconceptions with their own insight into teaching the scientific model.
Methodology
An exploratory case study was undertaken to gather rich information that may provide insight into the research problem. The purpose of qualitative studies like this is not to generalise, but to understand the participants' own insights. Accordingly, the size of the sample is limited to prevent overload of data and loss of depth (Cohen, Manion & Morrisen 2011).
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Nine Physical Sciences teachers who taught in the Further Education and Training Phase (FET), participated in the study. The schools were deliberately selected to represent public schools from different socio-economic groups, and a willing teacher per school was invited to participate. It was set as a requirement that participating teachers were qualified to teach Physical Sciences at the FET level. Convenient travel distances and accessibility to schools for the researcher were further criteria. The language medium was English in all these schools. Five of the schools were former socalled Model C schools in urban areas, while the other four schools were located in outer urban areas. Two of the suburban schools were located in upmarket areas, as measured by fees of more than R20 000 per year. The other three suburban schools served middle class families, as measured by annual fees of less than R20 000. The four peri-urban schools served learners from poor households and did not charge any fees. Table 1 provides a summary of teachers' biographical information and the background of the schools. Pseudonyms are used throughout to ensure anonymity. Table 1: Biographic data of teachers and school background. Teacher
Qualifications
Martha Neo
Degree Degree and Diploma Degree Diploma and Certificate Diploma and Certificate Diploma Diploma and Certificate Degree Two Diplomas
Owen Sipho Thembi Uve Philip Quinten Regina
Experience (years) 4 8
School location Suburban Suburban
Annual school fees (R) >20 000 >20 000
12 30
Suburban Suburban
