Enhancing Content Knowledge of In-service Science Teachers through Model and Modeling

The guiding question for this paper is; how does model and modelling enable student-teachers to develop a conceptual understanding of the cell as a structural and functional unit of living things? A teaching unit 'The Cell' was designed in view that models are a major teaching and learning tool for developing scientific thinking, whereas modelling means a process of forming representation. The teaching and learning strategies reported here encapsulated four modelling phases. Firstly, student-teachers modelled historical development of cell through a time line and role play and discussed the evolutionary and tentative nature of science. Secondly, the candy factory analogy provided a reference point to relate functional similarities between the units of a factory and cell organelles. Thirdly, students-teachers developed a 2D model to express their interpretation of the mental model. Fourthly, they critiqued their 2D model to develop a 3D model. Overall, a progression of conceptual understanding with distinct phases of enacting, building and rebuilding helped student teacher to conceptualize the structure and function of cell. Pre-post tests results show marked improvement in student-teachers' content knowledge on various aspects of structure and function of cell. Furthermore, teachers appreciated the effectiveness of the modelling process in enhancing their content knowledge and helping them develop understanding of the nature of model and modelling. Teachers also acknowledged the model as an effective teaching tool, which they could use in their classroom