COORDINATING REPRESENTATIONS AND LEARNING

The use of representations to fulfil meaningful learning has been highlighted in the field of biology education. Buckley (2000) asserted that the complexity and multiple levels of organization of biological phenomena are unable to be observed or experienced until representations can play the crucial role in helping students understand those biological concepts. As such, it may be worthwhile referring to the role of multiple representations in chemistry education, because chemistry educators have already drawn attention to the students’ misinterpretations in chemistry teaching and learning that can be caused when the links are not built between different levels of representation such as the macro and sub-micro levels (Davidowitz & Chittleborough, 2009). Constructing linkages across different levels of representations requires students to constantly transfer from one level of demonstration to another in order to accept the invisible and abstract chemical concepts. As such, this research had been guided by the notion that learners must direct their own learning as well as understand the various representations and how they relate to each other. It may be the case that understanding biological concepts can be challenging. The difficulty lies not only in interpreting different levels of representations for the biological content depicted, but also in switching and integrating each representation to develop holistic personal mental models of biology knowledge.

Identification of misconceptions or alternative conceptions is an initial step towards better science teaching and learning, for the knowledge of causes of alternative conceptions is essential for designing effective instructional strategies (Schönborn, Anderson, & Grayson, 2002). Based on the nature of biology as well as the analogical features of diagrams, learners’ difficulties in learning biology can be broadly classified in macroscopic, molecular, and textual levels:

(1) Representations at macroscopic level.

Students’ learning of biology concepts starts from observing visible phenomenon and tangible entities. Bruner (1962) emphasized the term general ideas (i.e. biological principles) that support the structuring of more specific knowledge interpreted from phenomena. Investigating students’ interpretation of science concepts at the macroscopic level provides novice students with an excellent starting point.

Thereafter, the subsequent content knowledge is easier recalled and used by the individual.

Photographs are the most frequent type of representations used in secondary biology textbooks (Roth, Bowen, & McGinn, 1999). An implication of this situation is the possibility that a photograph can achieve a powerful role as a representation of the real entity. However, the narrative and perceptual order of interpreting the image may cause misinterpretations for readers. It has been confirmed by Pozzer-Ardenghi and Roth (2005) that photographs are often taken as mechanical records of reality, that is, to serve as guarantors of truthful representation of real world. The abundant amount of information and salient details within a picture help students generate various kinds of interpretations depending on the individual’s focus.

Photographs and pictures can serve and make significant contributions to science learning because of their potential for improving learners’ retention of associated text (Peeck, 1993). Therefore, learners are less likely to achieve the scientific interpretation of the domain knowledge by making sense of the single meaning- making resource and representation. Another possibility of engendering misinterpretations is that research has shown students prefer textbooks that contain illustrations and inscriptions, namely photographs, caption, maps, tables. However, appropriate and necessary instructions on how to read and analyse photographs are not provided (Pozzer-Ardenghi & Roth, 2005; Pozzer & Roth, 2003). These studies above therefore provide important implications for investigating students’ alternative conceptions generated by photographic images at a phenomenological level.

(2) Representations at a molecular level.

The biological entities and processes at a molecular level are inherently complex because students can only observe them under a microscope beyond their direct experience. Unfortunately, only a very limited number of biology structures and processes may be observed under the simple microscope in schools where other more sophisticated equipment like electronic microscopes are not available. Though the learning of biological phenomena and facts are essential for long-term memory, various levels of biological organization cannot be fully explained and understood without examining those processes that are invisible to the eye. Scientific understanding of a particular sub-microscopic process is generally externalized in the

form of a pictorial representation which is a primary component depicting conceptual knowledge of biology (Kindfield, 1993). Students’ transition between the macroscopic and molecular representations has proved to be helpful for their conceptual understanding (Cook, Wiebe, & Carter, 2008).

The attainment targets for learning at the molecular level include: fostering systematic thinking and the ability to relate biological phenomena at various levels of biological organisation found to each other. However, students’ ability to explain at the sub-microscopic level was found to vary greatly in learning chemistry (Chittleborough & Treagust, 2008), so the same may be the case in learning biology. The value of biological diagrams was demonstrated in their ability to connect ideas and concepts. Particularly, diagrams have a role to play in connecting the macroscopic and sub-microscopic levels of representation. To develop scientific meanings, diagrams and illustrations are universally accepted as being beneficial learning tools in many disciplines (Stieff, Bateman, & Uttal, 2005). Most science teachers use diagrams frequently in their teaching on the assumption that they make things easier for students to understand. However, research suggests that a large number of students have difficulty understanding diagrams (Hartley, Wilke, Schramm, D'Avanzo, & Anderson, 2011). Diagrams usually delete unnecessary and irrelevant information to make the concept being taught more salient. The abstract science concepts and processes which cannot be photographed could therefore be represented in a diagram. Correct interpretation of diagrams requires transforming from one level of representation, and students have been found to have difficulties appreciating the role of the diagrams in explanations (Chittleborough & Treagust, 2008).

For students with little or no background knowledge, diagrams of the sub- microscopic level of representation appeared more difficult to interpret. One of the main difficulties facing learners’ interpretation is that they have inadequate knowledge about understanding the symbols and conventions made up of the diagrams (Gilbert, 2007; Tversky, Zacks, Lee, & Heiser, 2000). In particular, the techniques in designing a diagram may include: 1) the diagrammatic information could be exaggerated deliberately or inadvertently (e.g. Lowe, 1986; Wheeler & Hill, 1990); 2) the drawing techniques are utilized (e.g. Schollum, 1983); and 3) high level spatial ability is needed for understanding (e.g. Mathewson, 1999). Similarly,

Henderson (1999) recommended the importance of coding conventions used in reading scientific diagrams. The pedagogical value of diagrams should be considered in regards to their characteristics, purpose and usage. With the intention of making