Vygotsky (
1978) suggested the notion of the
zone of proximal development (ZPD), which is the distance between the actual and the potential developmental level. A student can reach the potential developmental level with the help of the scaffolding provided by an adult guide or by peers who are more capable. The provision of scaffolding can enhance the understanding of students who have not yet reached their potential developmental level and can help them to identify concepts (Hogan and Pressley
1997). In cognitive collaboration, scaffolding ensures a high-quality learning process in which the group members have different levels of cognitive ability (Wood et al.
1976). In this study, the deep learners in Group 6 prompted other group members to participate in the modeling process by producing the
nature of explanation (NE) and
asking questions (AQ), which involved the aims of the argumentative discourse, such as
sense-
making. These statements served as cognitive scaffolding, influencing the group dynamics and the modeling process, such as the model generation and elaboration phases.
Model Generation Phase
During the model generation phase, students are required to have creative and evaluative thinking skills. This is because model generation is not about a simple description of a phenomenon; instead, it is similar to the process of creating a new concept using various representation skills (Wells et al.
1995). In this phase, students collect data that can be used as evidence in order to produce the best model to describe the phenomenon (Louca et al.
2011). The knowledge to be used as evidence may be obtained through experiments, from a literature review, or it might already exist as prior knowledge (Justi and Gilbert
2002). After gathering evidence for the construction of a model, students need particular thinking skills to select appropriate model components. In other words, even though the students experience the same process for the collection of data, they use different amounts and kinds of data according to their knowledge bases, learning strategies, and thinking skills. Hence, deep learning approaches will be a critical element in thinking in-depth about the components of the model, with the goal of making sense of the target phenomenon.
With regard to the modeling process developed by Group 6, the first model was generated when a student who demonstrated a deep learning approach articulated statements involving
sense-
making around the principles of blood circulation. In five out of eight episodes, student A, a high-achieving student with a deep learning approach, was the first to demonstrate model generation. However, there were three episodes in which other students initiated the generation of the model; therefore, we need to analyze these episodes in order to examine the roles of the members and the cognitive collaboration that occurred. Student A generally initiated model generation and served as a role model for the other students. Student C, who had a deep learning approach but lacked a well-developed knowledge base, contributed to the generation of two models. This might be interpreted as the model generation skills shown by student A having provided cognitive scaffolding for student C. In addition, the model development was accompanied by students’ cognitive participation, triggered by their statements associated with DLA. This process is identified in Tables
6,
7, and
8. Three episodes were selected from the third lesson: One was about the heart–hand muscle circuit, another was about the heart–brain circuit, and the third was about pulmonary circulation.
Table 6
Episode 1 in lesson 3 (Systemic circulation: heart–hand muscle circuit)
1 | D | How should we draw? | | |
2 | A | Let’s draw it just like spreading through the whole body | NE-a | Model generation: [The heart’s pumping is the driving force of blood circulation] |
3 | D | Here and here (pointing with a pen) | | |
4 | A | Draw a line from here to here | | |
5 | C | I will draw the artery…comes out of the aorta | GT-a | Model elaboration: [Pathway of the heart–hand circuit: heart → aorta → (hand muscle)] |
Table 7
Episode 2 in lesson 3 (Systemic circulation: heart–brain circuit)
1 | A | It’s not the brain. Blood doesn’t spread from the brain. Where does blood come from? Now? | AQ-b | Model generation: [Heart–brain blood circulation initiates in the heart] |
2 | C | This is the aorta; that’s the superior vena cava | | |
3 | D | It’s (the brain) unique here | | |
4 | C | Hey, isn’t it thin here? | | |
5 | D | Let’s draw a line thicker on that place | | |
6 | C | There are only two vessels connecting here | MA-c |
Model evaluation at superficial component level [Pointing out the issue with drawing only two capillary vessels in the brain] |
Table 8
Episode 4 in lesson 3 (Pulmonary circulation)
1 | C | The pulmonary arteries are blue in color because blood in the pulmonary arteries goes out from the heart Blood flows through pulmonary arteries, pulmonary capillaries, pulmonary veins, left atrium, and left ventricle | NE-a | Model generation: [Pulmonary circulation initiates in the heart] Model elaboration: [Pathway of the pulmonary circulation: Heart → the pulmonary artery → the pulmonary capillary → the pulmonary vein → heart] |
2 | D | Where was the blood purified? | AQ-a | Stimulation of model elaboration |
3 | C | (pointing outward) From here | | Model elaboration: [Place of gas exchange (lungs)] |
4 | D | And then it flows into here | | |
5 | C | These are the pulmonary veins because the veins go into the heart. We should draw the veins, the left atrium, the left atrium, and the left ventricle | NE-a | Model elaboration: [Marking the oxygenated blood in the pulmonary vein, the left atrium, and the left ventricle] |
In Table
6, the statement types of the statements associated with DLA were provided in the coding column if the students’ statements were associated with DLA. In the model developed column, the corresponding modeling phase and the constructed group model were described. As in the other groups, students in Group 6 had difficulty in starting to draw the diagram at the beginning of the lesson (Table
6). At that time, student A, who had a deep learning approach, stated, “Let’s draw it just like spreading through the whole body,” (Line 2). This can be interpreted as the statements associated with DLA
focus on explanation of the mechanism (NE-a) since her statement pointed out that the heart’s pumping is the driving force of blood circulation. Her suggestion showed that she applied the data obtained from previous lessons to the new modeling activity and that she initiated the model generation regarding the heart–hand muscle circuit. An important feature must be noted here: Although all the students in Group 6 had obtained their data for the model generation from the same learning experiences, their performance in applying the data to the new model generation varied, depending on their learning approaches.
Student A’s statements associated with DLA (Line 2) established a foundation for the group model development and influenced the other students’ cognitions. However, her statement associated with DLA impacted the others in varying ways. For instance, student D accepted A’s statements associated with DLA regarding blood circulation literally, as the heart being the driving force. Student D, a surface learner, could only present blood spreading to the whole body, from the heart, across the whole paper (Line 3) but failed to note that the blood flow started from the aorta by reasoning out the relationship between the heart’s pumping and the heart’s structure. Contrastingly, student C, who has a deep learning approach, accepted student A’s statement in a different way. She integrated student A’s idea into her own conception that the blood from the heart flows to the particular branch of the body through the aorta. Consequently, student C demonstrated the statement associated with DLA present an idea (GT-a), which combined her own idea with A’s. Her attempt led to a group model elaboration by adding a model constituent to the existing model. This can be viewed as sense-making, which is one of the aims of argumentative discourse (Line 5).
During the process of model generation for the heart–brain circuit, student A again emphasized the pumping role of the heart (Table
7). She raised questions about the concept that “blood circulation initiates in the brain” presented in the group model, which contradicted her perception that “blood circulation initiates in the heart,” which was expressed in the previous lesson (Line 1). This statement associated with DLA involved
resolving discrepancies in knowledge (AQ-b) and triggered the generation of the heart–brain model. As with the episode described in Table
6, this statement associated with DLA provided a cognitive foundation for the other group members and enabled them to develop the heart–brain circuit model and to initiate another model. However, the students showed different reactions toward the same statement associated with DLA due to the differences in their own learning approaches.
Student D, with a surface learning approach, did not monitor student A’s statement associated with DLA but just rationalized the existing model by stating that the brain in their group model is uniquely different from the other ordinary brain (Line 3). Moreover, she did not modify the incorrect idea that “blood flow starts from the brain,” and she fabricated the drawing as if the cerebral vein was the aorta. In drawing the vessel that started from the brain, she attempted to make it thicker without any idea about the principles of blood circulation (Line 5). Contrastingly, student C, who has a deep learning approach, performed differently in response to student A’s statement associated with DLA, trying to interpret A’s statement associated with DLA against her own knowledge (Lines 2 and 4). This student understood the problem suggested by student A (Line 1) and discovered another problem in their group model, pointing out that there were only two capillaries in the brain (Line 6), which implied that she perceived the brain not as the driving force behind blood circulation but as one of the organs that receive oxygenated blood from the heart. As student C recognized and articulated the error in the group model, her statement was coded as evaluate task process (MA-c). This statement associated with DLA had the function of evaluating the model and causing the group model to be modified.
Two kinds of misconception were found in other groups. One was the linear circuit concept: “In the systemic circulation, the blood flows from the heart, goes through each organ and muscle in turn, and then flows back to the heart.” The other was the wrong driving power concept: “The oxygenated blood flows from the lungs to each organ and muscle.” As a matter of fact, these misconceptions are similar to those held by students related to blood circulation found by Chi et al. (
1994). Buckley (
2000) gave an explanation about the major misconceptions regarding blood circulation that were similar to those of Chi’s (
2005) ontological category explanation. Buckley (
2000) reported the misconception that blood circulation was the emergent process since the flow of blood to each organ occurs randomly due to the force of the heartbeat and the blood circulation, and the circulation is completed through continuous interaction between the constituents of the circulatory system such as the heart, vessels, and blood. In this study, some students, with the exception of Group 6, constructed group models that were quite different from the target model of this study.
However, it should be noted that the model constructed by Group 6, represented in the diagram, did not exhibit these errors. This is because students in Group 6 had a clear perception of the pumping role of the heart, which had been articulated by student A’s statement associated with DLA, as shown in the episodes reported in Tables
6 and
7. Accordingly, they realized that the heart–hand muscle circuit did not connect with the heart–brain circuit, and they understood that the lungs did not pump. In other words, due to student A’s statement associated with DLA, the students in Group 6 learned the sub-model of blood circulation and the systemic circuit as the emergent process. Therefore, their model had a branched systemic circulation pathway, and they showed the correct flow of oxygenated blood to each organ.
Student A’s statement associated with DLA not only initiated the model generation but also provided a scaffolding for the other students to participate in the modeling process that followed. During this process, however, students reacted differently, depending on their learning approaches. While student D, with a surface learning approach, accepted student A’s opinion literally, student C, with a deep learning approach, monitored student A’s statement associated with DLA and connected it to her own ideas.
Moreover, student A’s statement associated with DLA helped student C to initiate the modeling of the pulmonary circulation. As student C showed cognitive participation during the process of model generation and elaboration by applying the key principle that “the heart’s pumping is the driving force of blood circulation,” presented by student A, this also provided cognitive scaffolding. Episode 4 in Table
8 shows how student C contributed to the pulmonary model generation and elaboration phases. Student C initiated pulmonary model generation by suggesting the statements associated with DLA
focus on explanation of the mechanism (NE-a), which acted as a stimulant to others’ cognitions and encouraged others to participate actively in the modeling process (Line 1). She emphasized that the heart was the driving force of pulmonary circulation, stating, “blood in the pulmonary arteries goes out from the heart.” Student C applied the mechanism that was produced by student A during the initial systemic circulation modeling, using it to continue initiate the pulmonary circulation modeling. This implied that student C had internalized student A’s statement associated with DLA regarding the mechanism of the driving force of blood circulation. Furthermore, student C subsequently mentioned all the pathways of pulmonary circulation, and the model was then elaborated on in a series of cognitive participations by the other students.
In addition, it was noted that student D showed cognitive participation in the discussion on pulmonary circulation by stating the statement associated with DLA. Even though she did not initiate the modeling, she critically accepted student C’s statement. Student C’s argumentative participation in the previous modeling might have served a role as scaffolding for student D. Student D pointed out the mechanism of gas exchange in the lungs, which had been missing from student C’s statement associated with DLA. This kind of statement associated with DLA was an example of request information about mechanism (AQ-a), while the purpose of the argumentative discourse, sense-making, was well presented (Line 2). Student C articulated the gas exchange by pointing to the lung on the blood circulation diagram in response to student D’s question (Line 3). Thereafter, student D also pointed out the next pathway of pulmonary circulation (Line 4). Although this statement was not associated with DLA, it was a voluntary participation in the model development process during the model elaboration phase. In addition to student D’s statement, student C explained the reason why the place that student C had pointed to was the pulmonary vein (Line 5), so this was the statement associated with DLA focus on explanation of the mechanism (NE-a). Her statement was the summation of the group discussion, and, at the same time, it helped the students with their model elaboration (Line 5).
Model Elaboration Phase
In the science classroom, the questions generated by students lead to productive discussions and the meaningful construction of knowledge (Chin and Chia
2004). There are two kinds of deep approach questions in the statement associated with DLA: r
equest information about mechanism (AQ-a) and
resolve discrepancies in knowledge (AQ-b). Both of these questions involve the argumentative discourse aim of
sense-
making (Berland and Reiser
2011) because they originate from inquiries about the mechanism, and look for conflicts within the acquired knowledge, thereby intending to solve the problem. Students’ deep approach questions enable them to connect a new concept to their current understanding and to participate in group interaction during the process of resolving cognitive discrepancies (Chin and Chia
2004). In the case of Group 6, the
focus on explanation of the mechanism (NE-a) triggered another statement associated with DLA, playing the role of cognitive scaffolding to the other students. Thus, all students in Group 6 were able to participate in the reasoning process, and most eventually made contributions to the elaboration of the group model.
Episode 2 in the first lesson demonstrated this process (Table
9). The students attempted to construct an explanatory model regarding the one-way water flow mechanism by applying the inner structure of the siphon pump. Student A proposed the initial model, stating, “Water flows upwards in the straight pipe when the pump contracts,” and she asked a question involving
request information about mechanism (AQ-a), which stimulated the elaboration of the model (Line 1). Some chains of reasoning emerged because of this statement associated with DLA; that is, many students participated in the model elaboration process by referring to some statements associated with DLA. It is worth noting that students B and D, both surface learners, presented their own statements associated with DLA and showed cognitive participation during the process of group modeling.
Table 9
Episode 2 in lesson 1 (One-way water flow in the siphon pump)
1 | A | (Operating the pump) water flows upward by pushing it (pump) and putting it back…no…How does it work? | AQ-a | Stimulation of model elaboration: [Water flows up through the straight pipe when the pump contracts] |
2 | B | This is because the valves hit and push up the water. Right? | GT-a | Model elaboration: [When the pump contracts, the valve in straight pipe drives the water upward] |
3 | A | No, it (the valve of the straight pipe) closes when you push it, but it opens when it turns back | NE-a | Model elaboration: [Once the pump contracts, the valve in the straight pipe closes and vice versa |
4 | | Why does it work like this? | AQ-b | Stimulation of model elaboration |
5 | C | I think that water in here flows to here (curved pipe) when you push it (pump head). If you put away your hand, water flows upward and saves in here (pump head) | NE-a | Model elaboration: [Water flows up through the curved pipe when the pump contracts. Once the pump relaxes, water flows upward and is saved in the pump head.] |
6 | A | Can water be saved in the pump head? | | |
7 | C | Here (pump head) is the water | GT-a | Model elaboration: [When the pump contracts, water in the pump head flows toward the curved pipe.] |
8 | B | So the saving water flows down like this | GT-a |
9 | D | That’s why water drops from the cover | GT-a |
10 | A | Isn’t it because it (the valve in the curved pipe) closes and blocks water going downward? | NE-a | |
11 | C | So saving water in here drains out when pushing the pump. That’s why there is no water inside. Once it sucks again, water turns up again | NE-a | Model reinforcement |
12 | A | So (water) can’t drain out when the valve (in the straight pipe) closes | | |
13 | C | Yes | | |
14 | A | I see. Pushing it drives water out | | |
15 | D | That’s how water is saved in the pump | | |
Student B answered student A’s question about the mechanism and presented an explanatory idea by linking it to the pump structure as present an idea (GT-a), which elaborated on the model by adding the idea that the valve in the straight pipe influenced the water flow (Line 2). However, student B could not give a clear explanation about water flow in the pump; therefore, student A then presented a specific model showing that water flow was affected by the movement of the valve, and she expressed the statement associated with DLA focus on explanation of the mechanism (NE-a) when she tried to give an explanation about the mechanism related to the original questions (Line 3). At the same time, she asked an in-depth question seeking to resolve discrepancies in knowledge (AQ-b) when she noticed the gap between student B’s explanation (Line 2) and her own expected explanation (Line 4). This kind of question stimulated the model elaboration by drawing answers to explain the mechanisms of water flow and valve movement. To answer student A’s question, student C presented an idea that added to student B’s explanation (Line 2): She expressed that “water flows in a single direction with the contraction and relaxation of the pump as water can be saved in the pump head” (Line 5).
The question that was asked about the mechanism (Line 1) focused on a key model constituent regarding the one-way water flow in the pump. Moreover, another in-depth question (Line 4) required additional explanations about the group model in order to resolve knowledge gaps between themselves and others. In this way, these statements associated with DLA provided cognitive scaffolding for the elaboration of the model by asking others’ opinions. As the questions enlightened the students about the need to elaborate on the group models, these statements associated with DLA were regarded as metacognitive scaffolding. Kim and Hannafin (
2011) defined metacognitive scaffolding as providing help related to planning, evaluating, and reflecting in order to regulate the learning process. The group model was elaborated on and developed as a result of metacognitive scaffolding. For example, students’ perceptions developed from “water flows up through the straight pipe when the pump contracts” (Line 1) to “Water flows up through the straight pipe when the pump contracts. Once the pump relaxes, water flows upwards and can be saved in the pump head by closing the valve in the straight pipe.”
In addition, the discourse of students in Group 6 revealed that they shared an elaborated group model. Student A asked for new information about whether or not the pump head could save the water, confirming the information that had originated in the process of obtaining answers to the first question (Line 6). Almost at the same time, students B, C, and D expressed present an idea (GT-a) by answering, “When the pump contracts, water in the pump head flows toward the curved pipe” (Lines 7, 8, and 9). This showed that, with the exception of student A, everyone understood the idea that “the saved water flows out from the pump head when the pump contracts.” They contributed to the development of the group model because they added the content, “The valve movements enable one-way water flow, since water can be saved because of the valve movement.” Moreover, student C reinforced the explanatory model (Line 11), and the question raised by student A in the first place was completely resolved. The group model was completed because of the cognitive interactions within the group, and we could identify that the students in Group 6 were able to understand the mechanism of the target model.
A modeling activity by scientists is intended to construct explanations about a scientific phenomenon, and this can be the key to science learning (Harrison and Treagust
2000). This is because students practice evidence-based explanatory activities involving the integration of constructed knowledge and understanding through scientific inquiry in class (Windschitl et al.
2008). The students’ in-depth questions tend to ask “how” or “why” instead of “what.” Hence, an elaboration of the model was stimulated by requiring
sense-
making of the phenomenon. Answers to this type of question cannot simply describe the phenomenon; they also need to explain the mechanisms, thereby providing students with cognitive scaffolding. This is why a modeling process involving scientific explanations was conducted. In addition to scaffolding, cognitive participation was also found in students B and D, who were categorized as surface learners. Although they could not answer student A’s question in the beginning (Lines 1 and 4), they were later able to understand the mechanism of a one-way water flow in the pump because student C’s statement associated with DLA focus on the mechanism (Line 5) functioned as cognitive scaffolding. The findings showed that student B, C, and D participated in the model elaboration process by adding additional explanations of the mechanism (Lines 7, 8, and 9).