Combining different conceptual change methods within 5E model: a sample teaching design of ‘cell’ concept and its organelles

Since biology is a conceptual science, students may find biological concepts difficult. Therefore, students tend to memorize the biological concepts rather than using conceptual learning techniques (e.g. Özcan, 2000). That is, if students are unable to link the new knowledge with their pre-existing knowledge, (s)he prefers procedural learning (e.g. Kahveci & Ay, 2008). Despite the fact that student’s pre-existing idea is very crucial for further learning, an unstructured (or structured inaccurately) idea may generate an obstacle to achieve conceptual learning. Such incorrect views are generally named misconceptions, different from those accepted by scientific community. The misconceptions held by students are also pieces of intellectual thought in case of concepts (e.g. Çalık & Ayas, 2005; Yağbasan & Gülçiçek, 2003). Why misconceptions arise can be explained by several factors: student’s insufficient prior knowledge, his/her bias, his/her deficiency of motivation, teacher’s insufficient content knowledge, paying more attention to details instead of concepts, textbooks including misconceptions, using daily life language instead of scientific one and cultural factors. – meaning that some concepts may lead different meanings in various cultures (Aşçı et al., 2001; Goh et al., 1993; Storey, 1991; Harrison et al., 1999; Lubben et al., 1999).

Since students’ pre-existing conceptions are very significant for further learning, the subsequent perspectives have commonly been studied: structural and functional features of the “cell” (e.g. Doğru 2001; Kama, 2003; Marek, 1986), osmosis and diffusion (e.g. Atılboz, 2004; Marek et al., 1994; Odom & Barrow, 1995; Tarakçı et al., 1999; Westbrook & Marek, 1991), photosynthesis (e.g. Çapa, 2000; Köse, 2004), genetics (e.g. Lawson & Thompson, 1988; Lewis & Kattman, 2004; Özcan, 2000; Özdemir, 2005), ecology (e.g. Özkan, 2001), respiration (e.g. Sander, 1993; Akpınar, 2007), cell metabolism (e.g. Storey, 1991; Westbrook & Marek, 1992), cell division (e.g. Doğru, 2001, Baggot & Wright, 1996; Kindfield, 1994; Lewis & Wood-Rabinson, 2000; Yılmaz, 1998;) and physiological systems (e.g. Sungur, 2000; Teixeira, 2001; Tunnicliffe & Reiss, 1999). Of these perspectives, the cell and its organelles play a significant role in explaining many phenomena taking place in our bodies (e.g. Doğru, 2000; Kama, 2003; Marek, 1986). Further, they are the cornerstone for further learning such topics as genetics, reproduction, evolution, developing and growing and biotechnology.

When the first author noticed that most of science student teachers enrolled in ‘Biology Laboratory’ had misconceptions of the concept of the cell and its organelles, the authors looked for related literature to constitute a theoretical framework. Four misconceptions the first author determined are cited in the related references: (a) students place chloroplast to all plant cells (e.g. Kama, 2003) (b) many students believe that centrioles are responsible for cell division (e.g. Kama, 2003) (c) students draw oval or round shapes to illustrate the 'cell' (e.g. Clément, 2007; Flores, 2003), (4) the nucleus is always in the center of the cell (the fried-egg model) (e.g. Clément, 2007). The misconception that the ‘pore is viewed as a gap in cell wall’ has not been elicited previously. Widodo et al. (2002) stated that there is a gap between teacher’s theoretical knowledge and their practical classroom constructivist behavior; therefore, the authors attempt to present a sample teaching activity in order to inform the science and biology teachers on how to incorporate students’ misconceptions in their courses. A Turkish idiom illustrates the authors’ position ‘if everybody clears up his or her home front, there is no need to use a street sweeper’!

In brief, few studies have focused on the structure of cell and its organelles. The related studies have generally listed the misconceptions held by the students rather than producing alternative ways to remedy them. Generally, to accomplish conceptual change conceptual change text, analogy/model, worksheet, concept maps, etc. are used. But Chambers and Andre (1997) emphasized that first hand experience is more effective than conceptual change texts. Although using analogical reasoning or modeling is efficient in teaching science, most teachers do not use them as often as might be expected and tend to neglect their advantages (Harrison 1998; Treagust et al., 1998). Even if they attempt to exploit analogies/models, this frequently occurs in an unplanned manner (Duit, 1991; Nottis & McFarland 2001; Thiele & Treagust 1995). Also, the related literature stresses that using the only one conceptual change method may be boring to students, thereby; this may prevent to achieve effective results (Dole 2000; Huddle et al. 2000; Türk & Çalık, 2008).

Since students’ misconceptions are not remedied completely by means of the only one conceptual change method, the authors assume that using different conceptual methods embedded within 5E model will not only be more effective in enhancing students’ conceptual understanding but also may eliminate all students’ misconceptions. The aim of this study is to display a sample teaching of the cell concept and its organelles by combining different conceptual change methods (analogy, conceptual change text and worksheet) within the 5E model.