The Child's Ideas for 1. Under Foot

The Challenges of Developing Explanations Based on Data and Reasoning

Teachers can help students overcome these biases in memory by having them keep explicit records of their data and thinking—a practice that is critical to science

Theory building in science involves a constant interplay between making claims and gathering evidence, using one's imagination, reasoning, and prior knowledge to link and connect the two in complex ways. But what do children understand of this process?

Young children are constantly moving from evidence (specific observations) to claims (generalizations based on these observations) in their everyday lives. This is the basic process of inductive reasoning, which is at the heart of all learning from experience. For example, the child has repeated encounters with specific birds, each of which flies and concludes that all birds fly. Or the child has repeated encounters with nurses who are women, and concludes that all nurses are women. But children are not conscious of what they are doing in this process, which means they cannot engage in the self-conscious and more “controlled” inductive reasoning that is at the heart of modern science.

One challenge, then, is to get them to reflect on and conceptualize the process itself, explicitly distinguishing “the claims” from “the evidence.” This can be hard for children because for them claims and evidence blend seamlessly together into simply “the way things are.” Thus, when asked to explain how they know something, they might respond “I just know” rather than giving an appeal to specific evidence. Or when asked to explain an observation (Why do you think this cylinder is heavier?), they might just repeat the observation (because it feels heavier) rather than proposing a deeper explanation.

Inductive reasoning, of course, depends heavily upon our specific knowledge of an area, both for children and scientists. This is because our prior knowledge shapes what we see or pay attention to in any new situation. Both children and scientists must always be building on their prior knowledge and experience; at the same time, they often need to use these experiences to create new knowledge and to see things in new ways. Thus, another challenge for teachers is that, left unguided, children may notice or pay attention to things in a situation that the teacher thinks are irrelevant and fail to notice things that the teacher thinks are highly relevant. For example, in exploring water displacement, students might focus on how the object is put in the water or how heavy it is, and not pay attention to the subtler fact that the water is being displaced or pushed aside. Or when exploring a data table in search of patterns in the numbers, students might be looking for patterns based on addition or subtraction rather than multiplication or division; hence they may fail to find any meaningful generalization (such as when I double the volume of the water, I double its weight too).

This form of learning from experience—using new experiences to go beyond one's initial knowledge to develop new concepts and beliefs—is considerably more complex than simple inductive reasoning. It draws on many other thinking and reasoning abilities—such as engaging in thought experiments, making analogies, comparing and contrasting situations, and even engaging in simple deductive inferences in making predictions about what children expect will happen, given their existing beliefs. (The latter is a particularly powerful way of helping children notice and make changes in their own beliefs.) Children are actually able to engage in these other forms of reasoning as well, but they would not necessarily think to use them on their own. And rarely would they orchestrate them together in sustained reasoning about a new situation, which is what is needed in the process of belief revision and conceptual change. Hence, another challenge for teachers is to create the kinds of sustained classroom discussions, in which these forms of reasoning are productively combined.

Contributing to children's difficulty in distinguishing claims and evidence is the fact that knowledge acquisition in everyday life relies on their memory of experiences rather than careful record keeping, and memory is fundamentally integrative and fallible. That is, we don't store and remember every encounter with birds as separate events; rather we merge these together in our current knowledge of birds. Related to this, knowledge developed in everyday settings is subject to confirmation bias: the tendency to selectively attend to, highly value, and remember evidence consistent with a belief rather than evidence that is inconsistent with the belief. Students (and all people) would rather have an imperfect generalization (one that works only some of the time) rather than no generalization at all.

Thus, another challenge for teachers is helping students go beyond this confirmation bias and appreciate the importance of disconfirming evidence. Students may already have knowledge of counter–examples to generalizations from their experience (e.g., they may actually have met male nurses) that they have ignored or not considered. Teachers can help students overcome these biases in memory by having them keep explicit records of their data and thinking—a practice that is critical to science as well. This is one reason why the Inquiry Project curriculum stresses the use of student notebooks. This allows students in class discussions to productively consider, compare, and reflect on their data while considering alternative views. Teachers should also realize that students will not abandon one generalization until there is a better one available. That is why developing new ideas that are more consistent with (and explain) the entire pattern of data needs to go hand in hand with relinquishing old ones.

—Carol L. Smith