Material.
The material included two video-recorded semi-structured interviews provided by The Open University (The Open University, 2013) and dated July 2012. Technical apparatus included cameras, lights, and a microphone boom. For the practical task, a large plastic tank of water and 18 objects were used, classified according to the following categories: light floaters, heavy floaters, light sinkers, heavy sinkers. Detailed object list can be found in Appendix 1. Scales were used to compare weights in the latter part of the interview.
Procedure.
The interviews were conducted by Natalia Kucirkova, a doctoral student from The Open University, with the technical support of the film director, two camera operators, a sound recordist and an assistant. The interviewer had no previous knowledge of the participants. To protect the children's anonymity, only their first names and age were provided. Informed consent of parents for their children's participation to the interviews was obtained. The participants were informed of their right to withdraw at any moment from the study, in conformity to the BPS ethical guidelines. For both interviews, the technical setting, including the presence of the technical staff, was arranged so to be as unobtrusive as possible, and potential elements that could have inhibit the participants were considered (the interviews took part in a familiar settings).
The investigation involved a semi-structured interview and a practical task, and features three parts. Each part included three stages. The details of the interview protocol, provided by The Open University (2013), have been included in Appendix 2. Part A assess the participant’s initial understanding with light objects that float and heavy objects that sink. Part B assess the participant’s initial understanding with light objects that sink and heavy objects that float. In both parts, the experimenter presented the children with a set of objects and asked them whether they thought the object would sink or float and why. The children were then asked to test their prediction by placing each object in the tank of water, and to explain why the objects were floating or sinking. Part C focuses on developing children's understanding.
Both interviews were transcribed and the children's answers were coded. The number of answers for each category was counted.
Results.
Appendix 1 includes detailed data sheets for both participants that show both predictions and explanations for each object presented. The percentage of accuracy for Emily's prediction was 22.2% compared to 52.7% for Jessica's predictions. Most of the wrong answers concerned unfamiliar objects (the small wood block, the spanner) or objects whose weight was considered as more important in making a prediction than other characteristics (as for the tin lid, the white candle, the yoghurt pot, the needle and the coin)
Table 1 shows the number of explanations for each causal theme at stage 2 and stage 6-7 of the interviews, and the total number of explanations given by each participant.
Table 1. Coded results for Jessica and Emily, with frequencies and percentages.
Initial predictions and explanations.
At stage 2, Emily used only two causal themes, using Weight as the most frequent cause (77.7%) for objects to sink or float. By contrast, Jessica explanations at Stage 2 were more diversified, with references to both Holes and Material, but like Emily she explained sinking and floating mainly in terms of Weight (42.8%). For example, while recognizing that candles floats because they're made out of wax, and wax is light, she still predicted that the white candle would sink because it was “really heavy”.
After the cognitive challenge.
In stage 6/7, the number of causal themes used increased for both participants. The change in reasoning is particularly evident in Emily's case, with a shift from 77.7% to 9% for Weight and an increase from 22.2% to 63.6% for Material. She also used the theme Holes to explain why objects sink or float. The patterns of Jessica's explanations at this stage varied slightly, covering a wide range of themes; Weight, Material and Holes remained the most used theme, but she introduced a more complex scientific concept, that of Density.
Responses to scaffolded discussion.
This stage triggered a further change in both participants' explanations. While returning on the themes of Holes, Weight and Material, Jessica introduced a new theme, Shape, in her reasoning. For example, she hypothesized that the eraser sank because it wasn't curvy, while the grapefruit floated because, while being heavier than the eraser, it was shaped like a boat. Emily, on the other hand, seemed to apply systematically the idea that objects will sink if their inside “gets wet”, while objects without holes and waterproof will float.
Discussion.
In his theory of cognitive development, Piaget argued that children who have not yet reached the formal operation stage are bound to concrete experience in their understanding of how the world works. This is consistent with the accuracy of the participants' responses in the early stages of this investigation. Emily's predictions were based mainly on her concrete experience with the objects (their weight), while Jessica's answers were fairly diversified, indicating a more complex reasoning, and her predictions more accurate.
Both participants adjusted their reasoning when presented with challenging evidence in stage 6-7. Emily abandoned her initial hypotheses against the cognitive conflict described by Piaget, and referred to a new causal theme, that of Holes. However, a deeper analysis of her answers showed that there was no indication of an understanding of more complex scientific concepts, and that her reasoning remained bounded to concrete experience (Material). Rather than demonstrating a qualitative change in her thinking, she seemed to opt for an alternative explanation that could fit the actual evidence. On the other hand, Jessica's conceptual change is marked by the introduction of two new causal themes, those of Shape and Density. While her grasp of complex concepts is still uncertain (especially that of density), the boat effect and Archimede's principle are both indicated by Shelley as more sophisticated scientific reasoning on why things float or sink. Jessica's responses suggested a better understanding of scientific concepts, which could be explained in terms of both developed cognitive abilities and the effects of the cognitive challenge. Again, this is consistent with Piaget's predictions.
Jessica's conceptual change is further strengthened in the latter part of the investigation: unlike Emily, she developed her reasoning by shifting from explanations based on materials to explanations based on shape. For instance, while in stage 6-7 both children argued that candles floated because they were made out of the same material, wax, after the scaffolded discussion Jessica reasoned that candles floated because they were shaped “like a log” and were “a bit curvy”. Similarly, while Emily tended to generalise the knowledge that objects in which water couldn't get in would float in an inconsistent way (she argued that the rubber and the elastic band got wet) to fit the evidence with her current hypothesis, Jessica displayed a progress towards a more complex scientific reasoning.
While these findings supported the idea that collaborative working with adults is beneficial for cognitive development, Emily's lack of progresses in her scientific reasoning, by contrast, conflicted with Vygotsky's notion of zone of proximal development. Emily seemed unable to achieve a richer understanding of floating and sinking despite being assisted by an adult. Unlike Jessica, she took little benefit from her engagement with the experimenter, and this suggests a potential methodological problem with this study. The procedure involved placed excessive demands on the verbal and cognitive abilities of Emily, in terms of both difficulty and length of the interview, and perhaps a socio-cognitive conflict in the context of peer interaction could have been more suitable for a participant of this age. Moreover, Emily's limited knowledge of scientific concepts and linguistic competencies might have affected the results; it could be argued that, rather than reflecting a real difference in reasoning, her answers have been influenced by the limitedness of the language skills of a child of six.
There are other methodological problems to consider. The limitedness of the sample affected the generalizability of these findings: this analysis involved only two participants, of the same gender, and therefore does not provide a trend for the general population. Moreover, participants have been recruited from the same geographical area; as the study has been conducted in a Western cultural context, the effects of cultural biases on the discussion of this topic must be taken into consideration. Future research in this area could consider the impact of culture on scientific reasoning and its development.
However, even if the results of this study are to be considered within the boundaries of Western culture, they provide interesting insights into the developmental trend of children's scientific reasoning in this specific context.
Conclusions.
Results have shown that children's understanding of floating and sinking acquire complexity as their cognitive abilities develop, and that cognitive conflict provides an important context for conceptual change, as suggested by Piaget. However, findings on the role of scaffolded discussion in creating a zone of proximal development presented some inconsistencies with Vygotsky and Wood's predictions.
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References.
Doise, W. and Mugny, G. (1984), in Nunes, T. and Bryan, P. (2006), p. 292
Howe, C., Tolmie, A. and Anderson, A. (1991, 1992), in Nunes, T. and Bryan, P. (2006), p. 292-293
Inhelder, B. and Piaget, J. (1958), in Nunes, T. and Bryan, P. (2006), p. 288-289
Nunes, T. and Bryan, P. (2006) 'Mathematical and scientific thinking', in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/The Open University.
Oates, J. and Grayson, A. (2006) 'Introduction: perspectives on cognitive and language development', in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/The Open University.
Perret-Clermont, A. N. (1980), in Nunes, T. and Bryan, P. (2006), p. 292
Selley, N. (1993), cited in The Open University (2013) [online]
The Open University (2013), ED209 TMA 06 [online], available from https://learn2.open.ac.uk/mod/oucontent/view.php?id=212250 [accessed 10 July 2013]
Vygotsky, L. S. (1978), in Nunes, T. and Bryan, P. (2006), p. 294-295
Wood, D. (1988), in Oates, J. and Grayson, A. (2006), p. 19
Appendices.
Appendix 1: Data sheets (including object list and accuracy of predictions).
Appendix 2: Interview protocol.
Appendix 1. Data sheets (including object list and accuracy of predictions)
Appendix 2. Interview protocol.
Part A: assessing the participant’s initial understanding with light objects that float and heavy objects that sink
Stage 1: examining the objects. The child is presented with eight objects.
Stage 2: predicting what will happen and why. The child is asked to make a prediction about whether each object will float or sink. Natalia also asks them why they think the object will float or sink.
Stage 3: testing the predictions. One by one the objects are placed in a tank of water and the child is asked to comment on what has happened.
Part B: assessing the participant’s initial understanding with light objects that sink and heavy objects that float
Stage 4: examining the objects. The child is presented with 10 objects.
Stage 5: predicting what will happen and why. The child is asked to make a prediction about whether each object will float or sink. Natalia also asks them why they think the object will float or sink.
Stage 6: testing the predictions. One by one the objects are placed in a tank of water and the child is asked to comment on what has happened. It is likely that some of the children’s predictions here will not be confirmed. Natalia asks them to explain this result and may begin a ‘Stage 7’ type discussion for an object.
Part C: developing children’s understanding
Stage 7: a Piagetian approach – inducing cognitive conflict. Natalia draws to the child’s attention examples where their explanations are inconsistent and demonstrate an incomplete understanding. For example, a child who states that ‘heavy things sink’ may be asked to consider the heavy wood block, which floats, and the light needle, which sinks. This stage finishes with the child identifying the objects that floated and being asked to explain why all the items in this group floated. This is repeated for the objects that sank.
Stage 8: scaffolding children’s thinking. Natalia engages in a further discussion with the child (scales are used if the child has used the concept of weight in their explanations) in an attempt to help the child to take account of both size and weight, and to develop a more adequate (albeit incomplete) explanatory concept.
Stage 9: re-assessing the child’s understanding. Finally, the child is asked to explain why the objects that float and sink behave as they do.