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Asia-Pacific Forum
on Science Learning and Teaching, Volume 9, Issue 2, Article 12
(Dec., 2008) |
Now we will illustrate our developed teaching design.
Before handing out the worksheet, students are divided into small groups of 3-4 students. To activate students’ pre-existing knowledge, the following question at the top of the worksheet (Appendix 1) is asked: “Are there any differences between animal and plant cells?” By doing this, students become conscious of their peers’ pre-existing ideas.
Since the worksheet is handed out, students are asked to conduct the related activities in their small groups by following the given directions in the worksheet (Appendix 1). The teacher also asks probing questions to redirect the students’ investigations, if necessary, by refraining from any clue. After completing the activities, students are asked to respond the following questions: ‘Assume that your generated models illustrate animal and plant cells, which of them is an animal cell? Which of them is a plant cell? Please defend your response’, ‘In your generated models, please match your used materials with cell organelles by marking the type of cell with signal (X)’, ‘Since you tracked the same steps for both of the plates (steps 1-9), why did you follow the last three steps (10-12) for the only one plate? Please explain your reason’, ‘Could you compare the position of nucleus in the animal cell with that of the plant one? Please defend your response’ and ‘Taking into account the foregoing schema, please address the different organelles between the animal and plant cells’
Since each group completed the activities, they present their structured knowledge claims and share their ideas with their peers through a class discussion. Then, the teacher confirms/disconfirms students’ gained knowledge claims, so that the students compare their newly structured ideas with those presented by the teacher. Further, a transparent paper with plant and animal cells is represented (Figure 1). The teachers also stresses that various prototypes of 'cell' such as yeast cells, protozoa, nervous cells and so forth exist.
Using conceptual changing text (Appendix 2), the teacher fosters the students to elaborate their understanding of the concept 'cell' and its organelles to deeper and broader understanding and more information. This phase enables students to have an attempt to increase their conceptual understanding and to eliminate their misconceptions within multiple learning styles (e.g. Brinda, 2004; Harvey & Hodges, 1999).
To reinforce students’ newly constructed conceptions, the following question is used: ‘Please compare the factory with the structure of 'cell' in terms of their structural or functional features and then fill in the gaps’. To evaluate students’ conceptual understanding, the teacher can also exploit the concept map (see Figure 2) by removing some concepts and interrelationships. Further, to make students become conscious of their learning, they are asked to outline what they have learned.
